Yo propuse quedar antes de la reunión para revisar el informe.

Yes, Spanish often drops subject pronouns because the verb ending already shows who is doing the action. So Propuse quedar... is completely natural and probably more common in everyday speech.

Here, yo is included for one of these reasons:

• to add emphasis: I was the one who suggested it
• to create contrast: Yo propuse... pero nadie más quiso
• simply because the speaker chose to make the subject explicit

So Yo propuse quedar... and Propuse quedar... both work.

Propuse is the first-person singular preterite of proponer.

• proponer = to propose / to suggest
• propuse = I proposed / I suggested

The preterite is used here because it refers to a completed action in the past: at some point, the speaker made the suggestion.

Because proponer is an irregular verb in the preterite.

Its preterite stem is propus-, just like poner becomes pus-:

• yo propuse
• tú propusiste
• él/ella propuso
• nosotros propusimos
• vosotros propusisteis
• ellos propusieron

So proponí is not correct.

Here, quedar means to meet up or to arrange to meet.

So propuse quedar antes de la reunión means something like:

• I suggested meeting before the meeting
• I suggested that we meet beforehand

This is a very common use of quedar, especially in Spain.

Be careful, because quedar has several meanings in Spanish, such as:

• to remain
• to be left
• to agree to meet
• to suit / look good

In this sentence, the meaning is clearly to meet up.

After proponer, Spanish can use an infinitive to express the action that was proposed:

• Propuse quedar... = I suggested meeting...

This is a very natural structure.

A more explicit alternative is:

• Propuse que quedáramos antes de la reunión

That also means I suggested that we meet before the meeting.

So:

• proponer + infinitive = very common, compact
• proponer que + subjunctive = more explicit

Both are correct.

Because antes de is the normal structure before a noun.

• antes de la reunión = before the meeting

Compare:

• antes de + noun
  • antes de clase
  • antes de la cena
• antes de + infinitive
  • antes de salir
  • antes de hablar

You would not use antes que here, because la reunión is a noun phrase, not a full clause.

Para expresses purpose here:

• para revisar el informe = to review the report / in order to review the report

So the sentence explains why they wanted to meet before the meeting.

Spanish often uses:

• para + infinitive = in order to / to

Examples:

• Estudio para aprender
• Vinimos para ayudarte

So here:

• quedar antes de la reunión = meet before the meeting
• para revisar el informe = for the purpose of reviewing the report

This is a useful false-friend question.

In this context, revisar usually means:

• to review
• to check
• to go over
• to inspect

It does not usually mean to rewrite and improve a draft in the English sense of revise.

So revisar el informe is best understood as:

• review the report
• go over the report
• check the report

If you wanted the idea of study again / revise for an exam, Spanish often uses repasar instead.

Spanish uses definite articles more often than English.

Here, la reunión and el informe refer to specific things known in the context:

• la reunión = the meeting
• el informe = the report

Even when English might sometimes sound more flexible, Spanish usually prefers the article when the speaker and listener know what is being talked about.

So these sound natural:

• antes de la reunión
• revisar el informe

In theory, quedar can mean to remain or to stay, but not in this sentence.

Here, the context strongly points to quedar meaning to meet up:

• quedar antes de la reunión naturally means to meet before the meeting

If the meaning were to stay/remain, the sentence would usually need a different context or wording.

So for a learner, the safest reading here is:

• quedar = to meet up / to arrange to meet

Because the stress falls on the last syllable: reu-nión.

The written accent shows that the stress does not follow the default pattern.

Without going too deeply into spelling rules, the important point is:

• reunión is pronounced with the stress on -ón
• the accent mark tells you that clearly

This is also why related forms keep the written accent when needed, such as:

• reuniones has no written accent because the stress pattern changes naturally

So the accent in reunión is part of correct spelling and pronunciation.