I guess you are trying to learn French via English, even though your native language is Portuguese ? It will be very difficult.
As for your immediate problem, in English, tenses have two forms : the ordinary form and the progressive form. Progressive action (considered in progress at a given moment), is expressed by the progressive form of the verb:
Do not make any noise, he is sleeping.
Not so in French. We would say: ne faites pas de bruit, il dort.
So, no in the cases you mention, you do not use participe présent: j'étudie, je marche, etc..