Heyas, welcome to the community.
New to D&D eh?
Look into something called "Action Economy".
Basically, everyone has the same number and kind of actions. Action Economy deals with making best use of your actions and how to get more actions. That is one reason Spell Casters are so much more powerful than melee characters normally. They can get much bigger effects from their actions and have a lot of ways to push the envelope to get more actions. That doesn't mean non-magic characters are bad, they just need to work harder for similar payout and a good GM will make everyone useful (but you can help that along with good character development).