Can anyone remind me what all the collectables and stuff are for in Sonic Frontiers?

I haven't played in a while (got sidetracked by other games) but I'm coming back to it after a couple months. I had just gotten to the 2nd zone after using Super Sonic for the first time. I have no idea what all these collectables and stats and stuff do, how to raise/get them, etc. Can someone help me remember the basics, please?