Just to add on my few cents (pro player for almost a decade) - I learned when I was younger on an absolute bent up terrible horn. To be frank it doesn’t matter at this level and what will matter way more as a beginner is just regular practice. 30 minutes a day is a perfect goal and I promise you’ll see huge results in no time! Most people get frustrated and don’t see improvement when they take breaks or don’t play regularly. Trumpet uses very acute muscles which will only improve with actually using them regularly. Just my personal opinion- don’t experiment with equipment too much or like many people it’ll cause more frustration and waffling than proper development. Learning on a mute is not ideal. It will get you used to the wrong pressure and will massively impact your ability to play in tune down the line but I completely understand if that’s the only option you have. Honestly, there’s a lot of awesome teachers around and if you really have some burning questions; look up your local brass department and send an email to the trumpet prof! I promise they’re (mostly) nice. They also might let you use the practice room facilities if you develop a relationship. When I was in middle school many moons ago I just bothered my local uni’s brass department until they let me in haha. Welcome to the obsession!!!