Seems like your post got a little lost here. I'm still relatively new myself, but gotta try to help with what i know:
Examon is ok since you can easily get enough copies to MLB him, but he's rather slow and needs leader spot for the All 9 skill. Since you got Bellestarmon i'd recommend focus on her instead if possible, or Deltamon when you pull him from free ticket eggs.
Two good digimons you can work on are Craniummon and Shakamon. The former is very easy to make, you can get him drop on Imperialdramon PM island (white dragon holding the large sword) in Aegiomon's Quest and he has a very short evolution line. He's a really good tank to get started in PVP, or even to help you surviving some of the harder trials or event islands.
Shakamon on the other hand is really great for PVE, coupled with other reducers (Cherubimon Good is easy to get from free ticket eggs) you can quickly charge up your 9+2 combo or any other essential skill.
His evolution line is a bit longer starting from Tailmon, but it's definitely worth it.
After that you should start building two seperate teams, one for PVP and one for PVE.
Ofanimon, Highandromon and Craniummon are good to get started in PVP together with a healer and brown card generator. Best healer you can reliably get is Cerberumon Werewolfmode, you can make him through the currently last island on Aegiomon's Quest. Takes a bit of effort but it's worth it.
Not sure if there's any brown card generator to reliably get, maybe someone else can help here.
Through PVP you will get lots of Gold Disks and GSP Tickets which will help you building stronger teams in the long run. Lucemon from GSP eggs evolves to Lucemon Larva, which will become an essential for your PVP team in higher ranks. Other mons like Phelesmon or Daipenmon are also great for their 1-turn damage skills in PVP.
For PVE i'd say just keep going with the 9+2 combo, 1-2 reducers and while your stats are still low, Craniummon as tank. Death-X-Dorugoramon, evolving from Dorumon (Uncommon) in friend point eggs is something you can work on in the long run, i'm using him myself and he's great for PVE until you have some of the LR's like MGX.
That's all i got, hope someone more knowledgable than me can expand on any of this, or correct me if anything should be wrong.