How do I tell my friend I don’t want to play DND with them? /u/Extra_Display_2610 DnD: Roll for Initiative!

For some context, he invited me to a “one shot” where you play a one session campaign, and keep in mind, this was my first ever experience with dungeons and dragons, and had never played beforehand. I enjoyed the session, but I don’t think dnd is really my thing, and he’s already invited me to a campaign that he said is meant to last about a year, and I don’t really want to go, but I’d feel bad since he made a group chat about it and I am one of 4 people in it, and he has already given me a bag of dice for the campaign. Any advice?

Edit: for clarification, he is under the impression I am coming guaranteed, although I never actually confirmed I want to do the campaign

For some context, he invited me to a “one shot” where you play a one session campaign, and keep in mind, this was my first ever experience with dungeons and dragons, and had never played beforehand. I enjoyed the session, but I don’t think dnd is really my thing, and he’s already invited me to a campaign that he said is meant to last about a year, and I don’t really want to go, but I’d feel bad since he made a group chat about it and I am one of 4 people in it, and he has already given me a bag of dice for the campaign. Any advice?

Edit: for clarification, he is under the impression I am coming guaranteed, although I never actually confirmed I want to do the campaign