J.A.
The first time is so exciting especially for the parents, and the excitment may be overwhelming, he may be a little young yet BUT there are lots and lots of books and videos to read and show him that may ease his fears: My kids read Elmo's Potty Time and watched Bear and the Big Blue House. Make sure the potty is the right size and that he can sit on it himself. My 23 month old boy carries his very small potty around from room to room with him but his older sister who didn't train till she was almost 3 was totally fine with the regular toilet. I hope this helps a little, but I wouldn't push him if he is genuinely scared, he has plenty of time to grow a bit in size and maturity.