Any early game tips for a newbie?
Get 3 Pabumon
Evolve them to Motimon then Hagurumon then PlatinumSukamon. (don't grind them, just bring them with you or leave them in the farm to level up naturally though I do recommend bringing at least 1 or 2 with you to level up quicker than they would in the farm)
After Chapter 4 in the Hagurumon request where he asks you to find a gear, go into his dungeon, don't talk to him.
Run around the entrance area near the access point in his dungeon.
Grind PlatSuka until they learn Character Reversal (around level 25ish)
Then use 3 PlatSukamon in battle (in front, not reserve since support skills only work if they are in the frontlines), everytime a Vaccine type (Peckmon and Greymon mainly) appears, use Character Reversal on them to reverse their strengths and weaknesses. Dorugamon (the only other Digimon I saw at the entrance area of his dungeon) is already weak to Virus Type Moves from PlatSukamon.
Enjoy getting 4k EXP per battle and leveling up your reserves quite easily. Spend some time here digivolving and just having fun
. (party member will be low so you'll be making several trips to the DigiLab but you'll need to visit anyway to Digivolve so not a big deal).
Once you feel you have grinded enough/got enough Ultimates/whatever then complete the quest.
Warning: You won't be back there til MUCH later in the game and by then there will be better grind places. Just remember that.
All the early game tips you need there
If I buy this on the vita is there anything Ill regret having not played it on my ps4? Im thinking the Vita version might be a better option for me to play it on the go.
If you prefer to play it on the go then get the Vita version. The PS4 version has higher resolution and framerate but the Vita version is perfectly fine. I prefer console games personally since I'm not out enough that I need it on the go. (though I do have the JP Vita version but I played that on the big screen still
).
So yeah, get whichever one you prefer!