A few days ago, I hook up with a guy nearby. Unfortunately, I got too nervous and it wasn't a good experience, mainly because I'm not used to this (I hook up only once every other month maybe).
Anyway, I planned not to contact him again because I was embarrassed and thought he wouldn’t want to meet me again. But the day after, he sent me a message that I didn’t respond. Ever since then, he has sent me a gift a day.
He is an average guy and seems nice, but should I answer him?

My advice is to read the messages. They can give you a sense if what he's thinking. Especially if they're VMs (Voice Mails) you can get a better sense of tone. Basically do the messages come off as creepy, stalker like, desperate, lonely, casual, happy, sad, dangerous. You can get a feel of someone all from that.

Also when you say hook up do you mean a one night stand or a full date without sex? Let me tell you if it's a one night stand and he's as average as you claim then maybe he's confusing lust with love or he's thinking he can get back in bed with you. This could be a case where he enjoyed your company and wants to form a relationship, kind of like settling.

He could also be a psycho stalker with creeper tendencies. You gave so little information to go off its hard to actually suggest any real advice beside the first paragraph I wrote since everything else I wrote was built off a narrative in my head based in no real information.

I would suggest politely declining and moving on.

Major red flag vibes.

The gifts do seem a little obsessive, albeit with him still showing interest despite your perceived nervousness he might be genuine. In any case, communication might be helpful, even should you not wish to see him again, he at least deserves to hear that in clear terms.

that is a real red flag, you need to get away it gets me some possesive vibes

Maybe he just likes you. No need to panic. If you don't like him, then tell him. Politely. If he keeps contacting you, run.

Lmao stop hooking up with random people and get some real hobbies. The fuck you mean you're "only hooking up once every other month"? Ahahah, you're so unaware it's insane.

Get out of the escorting business while you can