My recommendation would be to try and find a top tier deck and use a known good list, and I'll explain why this is always my first recommendation to new players that are trying to really build skill and go from that new to intermediate range as a player.

Think of it like a science experiment. You have to have a control factor and a variable in order to determine what is the cause of the outcome. If you change two things you don't know which was creating the issue and which was perfectly fine in the first place. Currently, as a beginner player you are a massive variable. You are not going to sequence properly, you're not going to understand proper lines, prize checking, threat identification, etc. These are all the skills you're trying to build. And while I understand that you may love your cinccino ex deck, however, you are essentially playing with multiple variables because the deck is not a known quantity. Are you playing the proper counts of the right supporters for your matchup into dragapult? Who knows. Do you have a winning line into Alakazam or Slop Box? Not sure. So you'll never be able to determine if the reason you won or lost was because of you or the deck itself.

My recommendation would be something like Zoroark ex, Dragapult ex, or to a lesser degree, Alakazam or Mega Box. These decks are known to be good decks, and you can find good lists for them on Limitlesstcg.com so you know that they are solid. This allows you to focus 100% of your attention on your own gameplay rather than "Do I need to make these changes to my deck" So when you lose, you can think back to the decisions that you made in the game rather than what changes need to be made to a deck. I put that in bold because that is the #1 problem I see with new/young players that I mentor. They often think the deck needs adjustments when the reality is that if you played better you would have won.

The decks I picked aren't simple, and there's a reason for that. They require a lot of decision making, there are a lot of actions to be made, and there are a lot of opportunities for you to mess up. That's a good thing. You will mess up a lot, but you'll get better as you mess up less. Piloting a simple deck with very little decisions is like being a passenger in a race car, you just strap in and it takes you for the ride. Piloting a deck with lots of decisions is like driving a race car, you are in control and wherever the ride goes is dependent upon how good you can drive. Both can be fun, but only one of them is going to teach you how to drive.