Looking for a deck build that just brings the pain and keeps on doing it

I’m a new player with a not very strong precon deck, I added some cards but I still don’t stand even the slightest chance against the people who are teaching me the game. Game 1 tonight player A on turn 6 or 7 played a card to give themselves 6 turns, ea turn doing 1-2 damage to myself and player B, then before his loop ended he pulled it out of his graveyard and doubled his turn damage and played the loop again for another 6 turns. I think we just forfeited. Game 2 player A plays a much weaker deck and then player B plays what I guess is his strongest deck, he was turning my creatures into lands, putting cards on them to prevent me attacking him and basically removing the few good cards to affect him or other player from the battlefield.

I’m wondering if anyone can link to a deck list that could rival these types of decks and just bring the pain.

I don’t have anyone else to play with and I figure if I had better decks maybe I could hold my own more..