Shelley and Nita are great characters to use early on since they do so much damage; Nita having a slight advantage of being able to throw her bear over walls to reach the opponent and Shelley being able to shoot opponents behind walls with her special. Colt is high risk, high reward since he can chunk most characters but you have to be accurate; even with a quick shot you can miss.
Why wait for Brawl Stars?
When you can play SuperCats on Google Play? It plays similarly and can get you prepared for Brawl Stars' release.
Edit: This is not a paid ad. The game is just a rip off of Brawl Star so you can keep yourself entertained while you wait for Brawl Stars to release. Brawl Stars will be a much smoother version of what Super Cats is.
EDIT 2: It's out for Android now.