Hi Ilaria,
To say "I would like to…" you just need to use "chciałbym" (masculine) or "chciałabym" (feminine) + infinitive, e.g.:
Chciałbym być nauczycielem. (I'd like to be a teacher)
By the way, "chętnie chciałabym" doesn't sound good (I believe it is a tautological expression). Instead, you can use simply "bardzo chciałabym" (= I'd like to very much).
Powodzenia w nauce! :)