Answer:
1.) Comma.
2.) Lucy made creative, colorful Valentine’s Day cards for all of her classmates.
3.) The bus was hot crowded and loud, so we decided to get off and walk.
4.) Before gym class, the students seem happy, excited, and ready to play.
Only use for checking please. I'm confident you guys can do this! I'm struggling as well, and ik its hard to find motivation so... good luck! you can do this, i swear<33