Fake PayPal Overpayment on My First Commission

I just got my first art commission, and I don’t want to get in trouble, I don’t know what to do. I’ve seen that many people have gotten scammed this way. The buyer sent me 200 USD for a commission to PayPal, but I didn’t receive it. I got an email saying the money left the person’s account but couldn’t reach mine, so they had to send me 300 more, and then I should send 300 back to receive the 200. I showed the email to them, and the person asked me to either answer or delete the message. At that point I was already pretty sure it could be a scam, but I wanted to give them the benefit of the doubt and told them I preferred not to do either of those things. They said they had sent the 300, but then I got another email saying I have to send them the 300 back with my own money. I talked with my mom and she told me to block them and not do anything else. I know it’s a scam, but even if it is, I don’t want to get in legal trouble, because the email says that the (now 500) have left the person’s account but hasn’t reached mine. What should I do? I’ve also been told by other people that I should contact PayPal, but I’ve already blocked them. Is it okay if I don’t contact PayPal, unless the scammer tries to contact me again?