Learn Hardcore Portuguese (Portugal): Por enquanto, vou ler uma revista enquanto espero o autocarro. - For now, I am going to read a magazine while I wait for the bus.

Por enquanto = “for now / for the time being.” It’s a fixed adverbial phrase.
enquanto = “while,” a conjunction introducing the time clause. So there’s no redundancy: one says “for now,” the other says “while.”

Can I replace por enquanto with something else like entretanto or por agora?

Yes:

Entretanto = “meanwhile / in the meantime,” very common in Portugal here.
Por agora and para já = “for now,” also natural in European Portuguese.
Avoid confusing with no entanto (“however”), which marks contrast, not time.

Why is it vou ler instead of lerei?

In European Portuguese, the near future is usually ir + infinitive: vou ler (“I’m going to read”). The synthetic future (lerei) is grammatical but sounds formal/literary or emphatic in speech.

Could I say estou a ler instead of vou ler?

Estou a ler = “I’m reading (right now).” Use it if you’ve already started.
Vou ler = intention/plan for the near future.
Vou lendo suggests “I’ll (keep) reading little by little while I wait,” a gradual/ongoing nuance that’s also fine in EP.

Do I need to say eu (I) before vou?

No. Portuguese normally drops subject pronouns: Vou ler… is natural. Use eu only for emphasis or contrast (e.g., Eu vou, not someone else).

Should it be espero o autocarro or espero pelo autocarro?

Both are used in Portugal:

Standardly, “to wait for” = esperar por: espero pelo autocarro.
Esperar + direct object (espero o autocarro) is also very common and idiomatic in EP.
Don’t confuse with esperar para, which means “to wait to (do something),” e.g., esperar para apanhar o autocarro.

Is estar à espera de another good option?

Yes, very idiomatic in EP: Enquanto estou à espera do autocarro, vou ler uma revista. Note the contractions: à = a + a; do = de + o.

Why is it o autocarro and not um autocarro or just autocarro?

O autocarro = “the (expected/next) bus,” the usual way to refer to the service you’re waiting for.
Um autocarro would imply “some bus/any bus,” which is odd here.
Bare nouns are uncommon in this position in Portuguese; you generally use an article.

How would this sentence look in Brazilian Portuguese?

Bus: ônibus (not autocarro).
Progressive: estar + gerúndio is the norm. Example: Por enquanto, vou ler uma revista enquanto espero o ônibus.
Also fine: Por enquanto, estou lendo uma revista enquanto espero o ônibus.

Can I put the enquanto clause first? Any comma rules?

Yes: Enquanto espero o autocarro, vou ler uma revista.

When the enquanto clause comes first, put a comma after it.
No comma is needed before enquanto when it comes second.
A comma after initial Por enquanto is normal: Por enquanto, …

Can I use quando instead of enquanto to mean “while”?

Generally no. Enquanto expresses simultaneous actions (“while”).
Quando marks a time point/occasion (“when”). You could say Quando estiver à espera do autocarro, vou ler…, but that means “When I happen to be waiting…, I will read…,” not “during the waiting.”

Does enquanto ever mean “whereas”? What about enquanto que?

Yes, enquanto (and often enquanto que) can mark contrast (“whereas”) in other contexts. Here you need the temporal “while,” so just enquanto is perfect; enquanto que isn’t needed.

What about the gender/article of revista? Why uma?

Revista is feminine, so the indefinite article is uma. You usually need the article with a countable singular noun: vou ler uma revista (“I’ll read a magazine”).

Any quick pronunciation tips (European Portuguese)?

por enquanto ≈ “poor ehn-KWAN-too” (final -o like -oo)
vou ler ≈ “voh lehr”
revista ≈ “ruh-VEESH-tuh” (initial r is a throaty sound)
enquanto ≈ “eng-KWAN-too”
espero ≈ “ish-PEH-roo”
autocarro ≈ “ow-too-KAH-hoo” (the rr is a guttural/‘h’-like sound; final -o ≈ -oo)

Any spelling gotchas?

autocarro is one word (no hyphen).
enquanto is one word.
por enquanto is two words.
à espera (de) takes a grave accent on à (contraction of a + a).