Your post does come across like a 5 year old. So in this case you are actually going to need your mothers help. Being an obvious minor I would not suggest localbitcoins or an anonymous online transaction until you learn more about how BTC works.
Depending on your country there are exchanges, that you can use, you just need to open an account beforehand then transfer your BTC over. Google BTC exchange in your country, then do some research here on the forum to make sure they are legit. From there you will need to link to your moms banking to withdraw cash.
You can also try selling some of your bitcoins to trusted people in here through paypal or any other payment options that you prefer. Just be careful when doing online transactions and make sure you'd hire an escrow for you to avoid being scammed.
If you were to accept paypal anonymously from the forum make sure the member has a longstanding trusted reputation. Paypal is reversible, BTC is not. No one will escrow a BTC/Paypal exchange because it has a 6 month potential for chargeback.