Hey! I would say the main thing is to focus on why you enjoy the game and make sure it’s fun, this will give you the motivation in matches as well as setting yourself targets to aim for and reach. Often the motivation comes from these targets or goals and making steps to try nd get to them.
I also find setting these small targets even in matches can really help, you think more about each point and take your time. Lastly I think it’s good to really know your strengths and weakness during games and how to get your best shots into play more, this will help you in the last points jn games to find your strengths more often!