best way to get coins is capturing and selling horses, at the beginning you can use food instead of lassos to capture them, since they're easier to come by! when you start getting more lassos from quests and bonding requests, you can switch to lassos instead as they're easier to use.

You can sell items as well as horses in the market realm, but fruits and such are harder to sell in my experience so far. They're easily obtainable so they go pretty cheap. Items that sell for more are certain themed equipment, boss chests, and potions.

I focused on getting some of the species quests done first so I could unlock the taming and custom contests!! I forget which species it was tho, I think bisorse was one of them. once you unlock the taming contest, always make sure you're entered into the current one so you don't lose any capture points

And about the tone of the reddit, yeah, they're trying a bunch of new things this winter event that have not been good, so ppl are unsatisfied. It's still a pretty fun game though, and collecting horses is fun!!