אחרי כל המאמץ הזה, מגיע לך לנוח קצת.

A very literal breakdown is:

• אחרי = after
• כל = all
• המאמץ = the effort
• הזה = this
• מגיע = literally something like arrives / comes / is due
• לך = to you
• לנוח = to rest
• קצת = a little / a bit

So the sentence is built from something like:

After all this effort, it is due to you to rest a bit

Idiomatic English: After all this effort, you deserve to rest a bit.

Because הזה (this) normally goes with a definite noun in Hebrew.

So:

• מאמץ = effort
• המאמץ = the effort
• המאמץ הזה = this effort

Hebrew usually says the + noun + this, not noun + this.

That is why you get:

• הספר הזה = this book
• הבית הזה = this house
• המאמץ הזה = this effort

That is just the normal Hebrew pattern.

English:

• this effort

Hebrew:

• המאמץ הזה
• literally: the effort this

So in Hebrew, demonstratives like הזה / הזאת / האלה usually come after the noun.

Examples:

• הילד הזה = this boy
• הילדה הזאת = this girl
• הדברים האלה = these things

כל means all or every, depending on context.

Here, כל המאמץ הזה means all this effort.

A useful pattern is:

• כל + definite noun = all the ... / all this ...
• כל + indefinite singular noun = every ...

Compare:

• כל יום = every day
• כל היום = all day
• כל הכסף = all the money
• כל המאמץ הזה = all this effort

So the ה on המאמץ is completely normal here.

This is a very common Hebrew expression.

Literally, מגיע לך is something like:

• it comes to you
• it is due to you

But idiomatically, it often means:

• you deserve it
• you’re entitled to it

Examples:

• מגיע לך פרס = You deserve a prize
• מגיע לך חופש = You deserve a vacation / some time off
• מגיע לך לנוח = You deserve to rest

So in your sentence, מגיע לך לנוח קצת means you deserve to rest a bit.

Because in this expression, מגיע לך is not built like you arrive or you come. It works more like an impersonal expression: it is due to you.

That is why מגיע often appears in the masculine singular by default when there is no explicit noun after it.

For example:

• מגיע לך לנוח = You deserve to rest
• מגיע לך יותר = You deserve more

But if a specific noun is stated, the form can agree with that noun:

• מגיעה לך חופשה = You deserve a vacation
  (חופשה is feminine singular)
• מגיעים לך פיצויים = You deserve compensation
  (פיצויים is plural)

So here, with no noun stated, מגיע is the normal default form.

Because the expression is built with ל־ (to) + a pronoun.

So Hebrew says:

• מגיע לי = I deserve
• מגיע לך = you deserve
• מגיע לו = he deserves
• מגיע לה = she deserves

Literally this is closer to it is due to me / to you / to him / to her than to a simple subject-verb structure.

That is why לך is used, not אתה or את.

In unpointed Hebrew writing, לך can represent either:

• לְךָ = to you (masculine singular)
• לָךְ = to you (feminine singular)

So the written sentence can be said to either a man or a woman.

Only the pronunciation changes:

• to a man: magi'a lecha / lekha
• to a woman: magi'a lach

So מגיע לך לנוח קצת can mean:

• You deserve to rest a bit (to a man)
• You deserve to rest a bit (to a woman)

Same spelling, different pronunciation.

לנוח is the infinitive of the verb לנוח, meaning to rest.

The ל־ at the beginning often corresponds to English to in infinitives:

• ללכת = to go
• לאכול = to eat
• לישון = to sleep
• לנוח = to rest

After מגיע לך, Hebrew often uses an infinitive:

• מגיע לך לדעת = You deserve to know
• מגיע לך ליהנות = You deserve to enjoy yourself
• מגיע לך לנוח = You deserve to rest

קצת means a little, a bit.

Here it modifies לנוח:

• לנוח קצת = to rest a little / to rest a bit

Putting קצת at the end is very natural in Hebrew.

Compare:

• מגיע לך לנוח קצת = You deserve to rest a bit

You may also hear קצת in other positions, but this end position is simple and idiomatic.

Because the sentence is making a current judgment: right now, after all that effort, you deserve rest.

So:

• אחרי כל המאמץ הזה gives the background
• מגיע לך לנוח קצת gives the present conclusion

English does the same thing:

• After all that work, you deserve a break

Even though the work happened before, deserve is in the present.

The comma is natural because אחרי כל המאמץ הזה is an introductory phrase:

• After all this effort, ...

In Hebrew, commas after introductory phrases are common, especially when the phrase is a little longer.

So this is perfectly natural:

• אחרי כל המאמץ הזה, מגיע לך לנוח קצת.

In casual writing, some people might omit the comma, but with the comma it is clearer and more polished.

A useful pronunciation guide is:

Akharei kol hama'amatz haze, מגיע לך לנוח קצת

More carefully:

a-kha-REI kol ha-ma-A-matz ha-ZE, ma-GI-a le-kha / lakh la-NU-aḥ ktsat

A few notes:

• אחרי = akharei
• המאמץ has a break in the middle: ma'amatz
• מגיע is usually pronounced magi'a
• לנוח is lanuaḥ
• קצת is ktzat

If speaking to:

• a man: magi'a lekha / lecha
• a woman: magi'a lakh

Yes. This sentence is very natural and idiomatic, but Hebrew has other ways to express a similar idea.

For example:

• אחרי כל המאמץ הזה, אתה צריך לנוח קצת.
  After all this effort, you should rest a bit.

• אחרי כל המאמץ הזה, מגיעה לך מנוחה.
  After all this effort, you deserve some rest.

• אחרי כל המאמץ הזה, באמת מגיע לך לנוח.
  After all this effort, you really deserve to rest.

But מגיע לך לנוח קצת is especially common because it sounds warm, natural, and conversational.