This guy I like wants me to go to the beach with him, but I'm not really a beach person. Do you think it would be rude of me to suggest going for coffee instead? I really like him, so I don't want to mess it up. Thanks
"Sorry, I don't like the beach but I'd be glad to do something else like (insert activity here)!". He'll say "___ sounds good! Let's go!". Unless he doesn't like you and just has this odd fantasy of bringing someone to the beach, in which case, he'll find someone else to go with him.
May as well be yourself upfront - he will probably respect you for having an opinion rather than go along with sometjing you dont want to do. Yeah make an alternative suggestion so he knows you still want a date.