So im going to malaysia for a vacation if I want to scuba dive just ONCE do i have to obtain a diving license before I go or if im going as a tourist theres like a guide that can take you down? any info would be much appreciated.

It is possible to dive with an instructor without going through the complete set of lessons, at least in some resorts. I think they call it a resort dive. Ask the place where you are going about it. You probably have to get some instructions before the dive though.