Surely you’ve learned how to shield to protect yourself. Have you learned that yet? Good. You’ve learned.
Then next up is grabbing. And throwing!
Press the attack button while shielding...
And grab at your opponent!
If you press the attack button while shielding, you’ll grab. Give it a try next time you’re shielding.
Block your enemy’s attack with your shield!
Then just press the attack button to grab your enemy!
Tilt the Control Stick in any direction you like to throw!
Then pursue with combo attacks!
And so on.
Grabs are also effective against enemies that are protecting themselves with their own shields. Shield against attacks, then grab. Or dodge. If you can understand this flow, you’ll find they add a dimension that changes the simple charging attack.
At any rate, get in the habit of shielding when you’re in trouble. Then you can think about what comes next.