one time pad and caesar cipher

hello friends, lately I've been reading about one time pad and read somewhere that people usually use XOR in order to encrypt the message

if we use caesar cipher do we get a more secure encryption? or again it's the same thing? I mean, if the "attacker" finds out the key, then they won't have a problem finding out the encrypted message, or not?

I think I'm confused, what's the best way to encrypt a message using one time pad? is XOR the best way to go?

thanks in advance