syuumatu ni kouen de otouto no tiimu wo ouensimasu.

No. Normal Japanese is usually written without spaces:

週末に公園で弟のチームを応援します。

The spaces here are just for learners, so you can see the parts more easily.

Here is a simple breakdown:

• 週末に = on the weekend / at the weekend
• 公園で = at the park
• 弟のチームを = my younger brother’s team
• 応援します = support / cheer for

So the structure is basically:

[time] + [place] + [object] + [verb]

That is a very common Japanese sentence pattern.

に often marks a specific time when something happens.

So:

• 週末に = on the weekend

In beginner Japanese, time words are often split into two groups:

1. Time words that often take に

   • 3時に = at 3 o’clock
   • 月曜日に = on Monday

2. Time words that often do not need に

   • 今日 = today
   • 明日 = tomorrow
   • 毎週 = every week

With 週末, using に is very natural here.

Because で marks the place where an action happens.

• 公園で応援します = cheer/support at the park

A useful beginner contrast is:

• に = destination / existence / specific time
• で = place where an action is done

For example:

• 公園に行きます = go to the park
• 公園で遊びます = play at/in the park

In your sentence, cheering is an action happening at the park, so で is correct.

の links nouns together.

• 弟 = younger brother
• 弟のチーム = younger brother’s team

So の is often like English ’s or of.

Examples:

• 先生の本 = the teacher’s book
• 日本の文化 = Japanese culture / the culture of Japan

Here, 弟のチーム means the team that belongs to / is associated with my younger brother.

No. 弟 specifically means younger brother.

Japanese distinguishes older and younger siblings:

• 兄 = older brother
• 弟 = younger brother
• 姉 = older sister
• 妹 = younger sister

So this sentence specifically says younger brother’s team, not just brother’s team.

を marks the direct object of the verb—the thing receiving the action.

So:

• 弟のチームを応援します = support/cheer for my younger brother’s team

The team is what is being supported, so it takes を.

A few more examples:

• 本を読みます = read a book
• 音楽を聞きます = listen to music
• 友達を待ちます = wait for a friend

Even though English says cheer for someone, Japanese uses を with 応援する.

Because Japanese normally puts the main verb at the end of the sentence.

So instead of English order:

• I support my brother’s team at the park on the weekend

Japanese tends to do:

• [time] [place] [object] support

That is one of the biggest word-order differences between English and Japanese.

Yes, it often naturally means I support / will support the team, even though I is not stated.

Japanese very often omits the subject when it is obvious from context.

So this sentence could be understood as:

• I will cheer for my younger brother’s team at the park this weekend.
• or simply I cheer for my younger brother’s team at the park on weekends, depending on context

If the speaker wanted to say I more explicitly, they could say:

• 私は週末に公園で弟のチームを応援します。

But in many situations, 私は is unnecessary.

It can be present or future, depending on context.

Japanese non-past forms often cover both meanings:

• 応援します = support / will support

So it might mean:

• I support
• I will support
• I cheer for
• I will cheer for

The time expression 週末に helps you decide the most natural English translation in context.

The dictionary form is 応援する.

This is a する-verb:

• 応援 = support / cheering (noun)
• する = to do

Together:

• 応援する = to support / to cheer for

The polite form is:

• 応援します

This pattern is very common in Japanese:

• 勉強する = study
• 運動する = exercise
• 練習する = practice

Yes, Japanese word order is somewhat flexible, as long as the particles stay attached to the right words.

For example, these are all possible:

• 週末に公園で弟のチームを応援します。
• 弟のチームを週末に公園で応援します。
• 公園で週末に弟のチームを応援します。

They all mean roughly the same thing, but the nuance or emphasis may shift a little.

The most important thing is that the particles remain correct:

• 週末に
• 公園で
• 弟のチームを

By itself, 週末 can be interpreted in different ways depending on context.

• 週末に can mean on the weekend, this weekend, or sometimes on weekends
• If you want to be very clearly general, you might say 毎週末に = every weekend
• If you want to be clearly specific, context usually tells you, or you might say something like 今週末に = this weekend

So this sentence can sound a little broad on its own, and the exact English translation depends on context.

Not if you mean cheer at the park.

• 公園で応援します = cheer/support at the park
• 公園に行きます = go to the park

If you used 公園に directly with 応援します, it would sound wrong for this meaning because 応援する is an action done in a place, so the place marker should be で.