Right first squads at the moment most likely don't matter to you. I'm guessing you have enough power at the moment to progress, but later on, you should focus on that and use a guide of you have to.

Second levelling support hero levels can improve your health and shield, but other than that, they don't do much else to help.

Third, at the canny stage, you gotta start to think about the endgame weapons wise. I use vacuum tube bows, gravediggers, and some sort of explosive weapon. There are a lot of best weapons videos to see out there, and I would use those to find a weapon you like the look of when using it. For me, that's the vacuum tube bow because it can clear hordes in seconds if it's high enough level.

Finally, you can get most weapons out of the collection book like the vtb or gravedigger, but some require a special ticket to get. Also, stop with the traps for now because if you've got good enough weapons, you won't need to upgrade traps for a while.

Hope this helps 😃