Я учусь расставлять приоритеты.

Because учусь means I am learning or I study, while учу usually means I learn/memorize something or I teach depending on context.

• Я учусь расставлять приоритеты. = I am learning to set priorities.
• Я учу новые слова. = I am learning/memorizing new words.
• Я учу детей. = I teach children.

So in this sentence, the speaker is talking about their own learning process, which is why учусь is the natural choice.

The -сь is a short form of the reflexive particle -ся.

In dictionary form, the verb is учиться.
This often gives the verb a meaning like to learn, to study, or to be in the process of learning.

Compare:

• учить → to learn something / to teach
• учиться → to study, to be learning

In учусь, the ending is written as -сь instead of -ся because it comes after a vowel. That is just a normal spelling pattern.

Because after учиться you can use an infinitive to say learn to do something.

Pattern:

• учиться + infinitive

Examples:

• Я учусь готовить. = I am learning to cook.
• Она учится водить машину. = She is learning to drive.
• Мы учимся расставлять приоритеты. = We are learning to set priorities.

So расставлять is the action that the speaker is learning to do.

It means to set priorities, to prioritize, or more literally to arrange priorities.

The verb расставлять comes from расставить / расставлять, which often means:

• to place things in order
• to arrange
• to distribute

So расставлять приоритеты is a very natural Russian expression for deciding what matters most and what should come first.

This is an aspect question.

• расставлять = imperfective
• расставить = perfective

After учусь, Russian usually prefers the imperfective infinitive when talking about learning a skill or process.

So:

• Я учусь расставлять приоритеты. = I am learning how to prioritize / learning the skill of prioritizing.

Using расставить would sound less natural here, because the focus is not on one completed act of setting priorities, but on developing the ability in general.

Because the expression is normally used in the plural: расставлять приоритеты.

That matches English quite closely: to set priorities.
You usually do not have just one priority in this kind of phrase; you are ranking several things.

Singular приоритет is possible in other contexts, for example:

• Моя семья — мой главный приоритет. = My family is my main priority.

But in this sentence, plural is the standard choice.

It is in the accusative plural because it is the direct object of расставлять.

The verb расставлять is transitive, so it takes an object:

• расставлять что? → приоритеты

For inanimate masculine nouns in the plural, the accusative form looks the same as the nominative form:

• nominative plural: приоритеты
• accusative plural: приоритеты

So the form does not change here, even though the case is accusative.

Yes. Учусь is 1st person singular, present tense.

So Я учусь расставлять приоритеты means:

• I am learning to set priorities
• or sometimes I’m learning how to prioritize

Russian present tense often covers what English expresses with either I learn or I am learning, depending on context. Here, English usually prefers I am learning.

Yes, but it means something a little different.

• Я учусь расставлять приоритеты. = I am learning to set priorities.
  This sounds personal and practical: I am developing this skill.

• Я изучаю, как расставлять приоритеты. = I am studying how to set priorities.
  This sounds more like formal study, analysis, or research.

So учусь is better if you mean personal self-development.

No, Russian word order is fairly flexible, but Я учусь расставлять приоритеты is the most neutral and natural order.

You might also hear:

• Расставлять приоритеты я учусь.

This puts more emphasis on расставлять приоритеты, as if contrasting it with something else.

But for a learner, the basic version is the safest:

• Я учусь расставлять приоритеты.

Yes. That is one reason learners sometimes get confused.

Учиться can mean:

• to learn
• to study
• to be enrolled somewhere

Examples:

• Я учусь в университете. = I study at a university.
• Я учусь говорить по-русски. = I am learning to speak Russian.

In your sentence, because учусь is followed by an infinitive, the meaning is clearly I am learning to...

The stress is on the final -усь:

• учу́сь

And the whole sentence is pronounced roughly like:

• ya oo-CHOOS' ras-sta-VLYAT' pree-a-ree-TYE-ty

A few useful stress points:

• учу́сь
• расставля́ть
• приорите́ты

Stress matters in Russian, so it is worth learning these together with the words.