Participate
 

I want to participate in writing articles for school.
Is that ok?

Context. Participate means to take part in, so there needs to be something set up which others are doing, and you join it.

There is a neighbourhood group which cleans up the streets. I am going to participate.

Now if writing articles for school is an activity for several people, then you may want to participate as well.

If it is a lone effort on your behalf, then perhaps:

I want to take the initiative and write......

It's OK, so long as context infers you're joining a group effort (as Perikles said).

If that context hasn't been established, you could say:
I want to participate in the group that writes articles ...
A group writes articles ... and I want to participate.

If you want to avoid 'participate', but still want to infer that others are writing besides yourself, you can say:
I want to help with writing articles ...
I want to help write articles ...

So, I want to participe writing articles is incorrect I guess.

Imply would be the standard usage.