Single player to get to know the basics, then I'd try official (it's very grindy but not bad if you get a tribe together) or you have player dedicated servers that vary the stats on the game. Your player will have higher health weight ect and same goes for your dinosaurs, basically the same at a faster pace if you prefer to get into pvp a lot faster.
Then there's pve, has good points like you can't be raided or attack others unless you agree to a war, gets boring quite fast though