Тебе стоит приложить усилие, чтобы исправить ошибку в отчёте.

In Russian, the pattern (кому) стоит + infinitive treats the person as the one “for whom it is worth/appropriate” to do something. That person goes in the dative:

• Тебе стоит… = It would be worth it for you to… / You should… Using ты would require a different structure, e.g. Ты должен… (You must…) or Ты должен постараться… (You should try…).

Стоит here is an impersonal “modal” meaning it’s worth it / it’s advisable / you should. It’s typically softer than нужно (need to) or должен (must).

• Тебе стоит приложить усилия… suggests advice/recommendation rather than obligation.

Yes.

• Тебе стоит… is informal singular (to you).
• Вам стоит… is either polite singular (to you, formal) or plural (to you all).
  Everything else can stay the same.

The most common idiom is приложить усилия (plural) = make an effort / put in effort.
Приложить усилие (singular) is possible but sounds less idiomatic to many speakers and can feel like one specific effort rather than “effort in general.” A very natural version is:

• Тебе стоит приложить усилия, чтобы исправить ошибку в отчёте.

Приложить (perfective) presents the effort as a single, bounded action: put in the effort (and get it done).
Imperfective options change the nuance:

• прилагать усилия (imperfective) = to be making efforts / to make efforts in general / repeatedly. So:
• Тебе стоит прилагать усилия… sounds like ongoing or habitual effort, not just “do it now and finish.”

After чтобы, Russian often uses an infinitive when the subject is understood (especially when it’s the same person being advised):

• …чтобы исправить ошибку… = in order to fix the mistake… You can also use a finite verb if you want to be more explicit or stylistically different:
• …чтобы ты исправил ошибку… That version can sound a bit more pointed/emphatic, depending on context.

Исправить (perfective) means fix it (successfully, completed)—a finished result.
Исправлять (imperfective) would mean be fixing / fix (process or repeated), which is less natural if you mean “correct that one mistake in the report” as a completed task.
For a single concrete correction, исправить ошибку is the standard choice.

Because исправить is a transitive verb meaning to correct/fix something, and the direct object takes the accusative:

• исправить (что?) ошибку If you used a different verb, the case could change, e.g. избавиться от ошибки uses от + genitive.

в отчёте means in the report (location/containment). With в meaning “in/inside,” Russian uses the prepositional case for a static location:

• в (чём?) отчёте If you meant “into the report” (adding something), you’d often use accusative:
• внести правку в отчёт = make an edit to the report / enter a correction into the report (direction/target).

Because чтобы исправить ошибку в отчёте is a dependent purpose clause (or purpose phrase) attached to the main clause. Russian normally separates it with a comma:

• Тебе стоит приложить усилия, чтобы…

Yes, word order is fairly flexible, but it changes emphasis:

• Neutral: …исправить ошибку в отчёте (the mistake is located in the report)
• Emphasize the report: …исправить в отчёте ошибку (focuses on “in the report” as the place you should fix it)
• Emphasize the mistake: …ошибку в отчёте исправить (more stylistic; can sound emphatic)