Need help with a guy, not sure what to do now..

Hey there! First time redditor (If that's a word) and new to whole gay community, but anyways I just wanted some advice to a problem I'm having.I'm a 17 year old senior in Hawaii and I have this crush on a guy from another school nearby. He is a senior as well, In band, plays the same instrument, seems like a sweet guy and I honestly want to get to know him but I have a hard time talking to him.Saw each other a few times, but no introductions. We met properly at his aloha concert last year where I just introduced myself and everything but nothing much because I was dating my ex who was also in the band. We ended up seeing each other again at the SAT and got to talk a little more, still dating my ex so nothing romantic. Added each other on FB and talked now and then on messenger.Jump to a few months later and my ex breaks up with me. I decide to try talk to more guys months after to test the waters a bit. I remember the guy and end up messaging him through FB. This was right after a big marching band performance so I congratulate him and we end up talking about band things for 6 hours together. I was happy to finally have a full conversation and things seemed to be going well.Then that was it. Nothing after much. We had another performance soon after and I messaged him again about it but it was barely even 10 mins of conversation. My friends push me to message him again so I go with a simple "Hey!" and 1 day later he finally messages back with "hola". I reply soon after with "Oh hey! What'cha up to?" anddddd nothing. He never looked at it and never replied. We just kinda ended there and that was it.The main problem is I have no clue what to say to him. I want to tell him I like him and ask him on a date but at the same time I don't want to lose a friend. A lot of my friends say to go for it and ask him out or tell him I like him but others say to wait it out or just move on because he's focused on school. I'm torn because I honestly am the most indecisive person in the world. I know he is gay because I asked a ton of his friends if he was, even him and my ex even had a sexual thing together. He just doesn't seems interested, he never replied back and there are times where he takes super long to message or doesn't message back at all. I wanted to at least get through the surface level of just looks and band. I wanted to learn more about him and who he is I guess. It just sucks we never got to be able to do that.So I'd appreciate any sort of advice and thank you for taking the time to read my very first post on Reddit lol.TL;DR: Cute band guy from other school, kinda just stopped talking, not sure if I should say things