I just got my first 99 (Pup) and will be getting dnc to 99 in a couple of days , now what? I'm kinda overwhelmed where to start. Any suggestions?

Edika,
Well, I think first priority after reaching 99 is making sure you gear/skill up. Also, deciding if you really like playing those jobs, or if you'd like to explore others for various reasons. Below is a good post by Kutal outlining where we can start helping players get seals/atmas from Abyssea.
Best,
Ashbery