What is incumbent upon me regarding missed prayers and fasting, and am I obligated to feed ten needy persons despite not possessing sufficient funds and without my parents' knowledge?

Praise be to Allah, who has blessed you with repentance and guidance. It is not necessary to make up for the days you masturbated during Ramadan, according to the more preponderant opinion. As for the prayers you performed without performing ghusl, they are invalid due to the absence of the purity condition, and it is obligatory to make them up according to the majority of scholars, which is the more cautious approach. If you do not know their number, then make up what you believe is sufficient to clear your conscience. You are not required to feed the poor.