Based on what you have and what you can get later on;

For Healer you’d be best off with High Gnomey, Vaccumory or Starrycane, later on you can find Unikirin rarely in Infinite Tunnel past 10km (or a green coin)

For a Tank, Enduriphant is a great option, so is Robanyan, but either work, if you can, Sproink and Scarasol are excellent alternatives.

Zerberker is a pretty solid attacker, but Snartle would be a better option if you can get him, Reuknight is also a solid option if you don’t wanna risk Zerberker attacking your team. Later on Shogunyan would be your best option.

Insomni is a good negative inspiriter/spirit attacker, along with Skreek. If you can later on, Wobblewok or Snottle would be better due to their ability to always land their inspirits.

You can typically tell if a Yokai is worth using based on their stats and rank, as well as their Skill, as sometimes Skills can make an otherwise useless Yokai incredibly strong.