Guy wont stop texting me! PLEASE HELP!

I gave my number to a guy on Friday and he won’t stop texting me. I go to school and on the bus and youth group with this guy and he doesn’t really have very many friends and he asked for my number so I gave it to him not realizing he was into me and thinking he would like never text me and now he persistently keeps texting me hey and how’s your weekend and it’s really annoying. I don’t know how to tell him I’m really not into him nicely. I just haven’t been answering his texts and I was away this weekend so I have an excuse. Please help! I don’t want to be rude and I see this guy about once a week so I can’t just avoid him forever. (He’s also a grade younger than me and I hardly want to be friends with him 😫😫😫) PLEASE HELP ME!