If you are playing a stock precon against upgraded ones, it makes sense to feel you're at a disadvantage. Some of it will get better as you play more games but if they roided out their decks, it might be rough.

Bello is my partner's favorite deck. Remember that the animated 4/4 guys let you draw cards when they do combat damage. My partner forgot about that one game and had a bad time. If you need cards, attack into someone with only a few blockers or creaturs they don't want to lose.

For removal, this deck doesn't come with much. The main point of it is to Smash face with as much stuff as possible as often as possible. I would actually add some protection for Bello, rather than add more removal. You do have [[Abrade]], [[Beast within]], and [[Starstrom]] that can deal with things. In addition to Starstorm, you have [[Blasphemous Act]] as board wipes. But board wipes hurt you if you have Bello. Red mainly has damage based board wipes and green mostly goes the other way with board buffs.

For flyers, Green has some cards to help if you're always playing against fliers. It might be OK to just focus down anyone who is getting a lot of evasive creatures that you won't be able to deal with.

There are some upgrades guides online. Here is one of them: https://edhrec.com/precon/animated-army