Ainda assim, estou contente, porque sem este caminho não teria conhecido tanta gente boa.

Ainda assim is very close to English even so / still / nevertheless.

• It links two ideas where the second goes against expectations created by the first.
• In your sentence, it means: “Even so, I’m happy …” (despite something negative implied before).

Differences:

• ainda assim – very common, slightly neutral/formal; good in speech and writing.
• mesmo assim – also very common; often sounds a bit more colloquial or emotional. In most cases, you can swap ainda assim with mesmo assim without changing much:
  
  • Ainda assim, estou contente.
  • Mesmo assim, estou contente.
• apesar disso – closer to in spite of that / despite that. It sounds a bit more formal and is used more when you’re explicitly contrasting with something mentioned just before:
  
  • Foi muito difícil; apesar disso, estou contente.

In this sentence, ainda assim gives a smooth, slightly reflective tone: “even so, I’m (still) happy …”.

The comma is stylistically very natural here and would almost always be written:

• Ainda assim, estou contente …

It reflects a small pause in speech.

However, writing it without the comma is not grammatically wrong:

• Ainda assim estou contente …

This just feels a bit more “rushed” or less clearly separated in writing. In most careful European Portuguese, you’ll see a comma after a sentence‑initial connector like ainda assim, por isso, no entanto, etc.

In Portuguese, porque meaning because usually introduces a subordinate clause of cause, and it can take a comma, especially when the cause is felt as extra information or an explanation, like here:

• … estou contente, porque sem este caminho não teria conhecido…

The comma here separates:

• main clause: estou contente
• explanatory cause: porque sem este caminho…

You could also omit the comma:

• … estou contente porque sem este caminho não teria conhecido…

Both are acceptable.
With the comma, the reason sounds a bit more like an added explanation; without it, the cause is more tightly bound to the main clause.

So, unlike the stricter “no comma before because” advice in some English contexts, Portuguese allows (and very often uses) the comma before porque.

Teria conhecido is the conditional perfect (in Portuguese grammar often called condicional composto):

• auxiliary verb ter in the conditional: teria
• past participle of the main verb: conhecido

So:

• teria conhecido = would have met

Formation pattern:

• ter in conditional (teria, terias, teria, teríamos, teríeis, teriam)
• • past participle (falado, comido, partido, conhecido etc.)

In your sentence, não teria conhecido expresses a hypothetical past: something that didn’t happen, but could have happened in a different situation.

Não conheceria corresponds to simple conditional: would not meet / would not know (general or future‑in‑the‑past).

But here we’re talking about a past hypothetical result:

• English: “without this path I *wouldn’t have met so many good people.”*
• Portuguese: sem este caminho não teria conhecido tanta gente boa.

So:

• não conheceria → more like “I wouldn’t meet” (general, not tied to a specific unreal past)
• não teria conhecido → “I wouldn’t have met” (specific unreal situation in the past)

Because the speaker is reflecting on something that has already happened (meeting those people), the conditional perfect (teria conhecido) is the natural choice.

Sem este caminho literally means without this path/way/road. It’s a common and very compact way to express a counterfactual condition:

• Sem este caminho, não teria conhecido…
  ≈ “If it weren’t for this path, I wouldn’t have met…”

You could indeed say, more explicitly:

• Se não fosse por este caminho, não teria conhecido…
• Se não tivesse seguido este caminho, não teria conhecido…

These are all correct, but:

• sem + noun is shorter, very idiomatic, and slightly more literary or reflective in tone.

So sem este caminho elegantly encodes the idea “if it hadn’t been for this path / without following this path”.

In Portuguese:

• estar is used for temporary states, feelings, moods, or results of situations.
• ser is used for permanent characteristics, definitions, identity.

Contente is usually treated as a state (how you feel now) rather than a deep character trait. So you say:

• Estou contente. – I’m (feeling) happy / pleased (now, in this situation).

Using sou contente is possible but unusual and sounds like:

• a description of your general disposition (“I’m a contented / generally cheerful person”), and
• even then, most speakers would prefer sou uma pessoa contente.

In this sentence, the speaker is reacting to a particular life situation, so estou contente is the natural form.

Both can mean happy, but there is a nuance:

• contente often suggests pleased / satisfied / glad, sometimes quieter or more moderate happiness.
• feliz is more like truly happy / joyful, often a bit stronger or broader.

You could say:

• Ainda assim, estou feliz… – also correct, slightly more emphatic.

But estou contente sounds like a calm, reflective satisfaction: “Even so, I’m (still) glad / content.”

Both are grammatically correct:

• tanta gente boa
• tantas pessoas boas

Differences in feel:

• gente = “people” as a collective. It’s very common in informal and neutral speech, especially when talking about groups in a warm or general way.
• pessoas = “people” as individual persons, a bit more concrete, sometimes slightly more formal.

Tanta gente boa sounds:

• warm, affectionate, a bit more colloquial/natural in everyday speech.

Tantas pessoas boas is:

• perfectly correct, but feels slightly more neutral or “countable”.

In this sentence, tanta gente boa nicely matches the emotional, reflective tone.

In Portuguese, gente is grammatically singular and feminine, even though it refers to many people:

• esta gente (not estas gentes in everyday speech)
• boa gente / gente boa

So:

• tanta agrees with gente (feminine singular)
• boa also agrees with gente (feminine singular)

That’s why we have:

• tanta gente boa – literally “so much good people”, but with singular agreement.

If you wanted explicit plural agreement, you’d use pessoas:

• tantas pessoas boas – here, tantas and boas are plural feminine to match pessoas.

In Portuguese, a personal a is common before specific, usually human direct objects:

• Conheci a Maria.
• Vi o João ontem.

But with an indefinite, non‑specific group like tanta gente boa, the a is normally not used:

• Não teria conhecido tanta gente boa. ✔️
• Não teria conhecido a tanta gente boa. – sounds odd or overly marked.

If you specify the group more clearly (“those people”), the a can appear:

• Não teria conhecido a essa gente boa. (more specific: that good crowd)

In your sentence, tanta gente boa is a general, indefinite group, so no personal a is used.

Yes, tanta boa gente is also correct and idiomatic.

Both:

• tanta gente boa
• tanta boa gente

mean essentially so many good people.

Nuance:

• tanta gente boa is the most straightforward, neutral order.
• tanta boa gente sounds slightly more poetic or expressive, and is fairly common in songs, literature, and affectionate speech.

In your sentence, you could say:

• … não teria conhecido tanta gente boa. (more neutral)
• … não teria conhecido tanta boa gente. (a bit more stylistic/expressive)

Both are fine in European Portuguese.