Is it correct to say :
j'ai déjà étudié les sciences pour me préparer. -- i have already studied science to prepare myself

Yes, this is correct.

Bonjour

I have already studied sciences to prepare myself.

J'ai déjà étudié les sciences pour me préparer. ► CORRECT

☺☺☺

ok so from je m'apple it should be mon nom

then from je suis age de turn it to mon âge

then from mon anniversaire tombe en turn it that one would be right but it doesn't really fall exactly, like it just says my birthday falls under, but i suppose u r right, but if u want it to be exact then it should be mon anniversaire

then i'm a bit confused on the last part, so first u said u like the rounge (idk) then it says, i like white violet, and my favorite subject is french

26. arriver

27. faire

28.un roi de la france.

29. les personnes des pays comme l\'egypte

30. true

32.followed

33.followed

34. je vais étudier

35. fera

36. ira

37.conduire