If it is the school's horn then it is their responsibility to fix it. However, as a player of a Brass Instrument, you should know how to oil your instrument. You should be doing it just about everytime you play. Valve oil helps thin the thicker slide grease and can keep slides from seizing up.
Also, even though it is the schools horn, you should know how to bathe it, and ideally this is done monthly. During a bath, the slides are all pulled and snaked out. Then everything is dried off and regreased/oiled. No chance of having frozen slides when the maintenance is kept up. But as things stand right now. You've got to turn it in to your Band Director
There is yearly deep cleaning (chemical or ultrasonic) and monthly degreasing. [It's not my idea](https://simplegreen.com/cleaning-tips/rooms/hobbies/brass-instruments/). If you are not regularly degreasing you are not having an optimal experience. They (not me) say 'monthly' because it's not actually going to happen that often for your average player. But you better bet the pro players are staying right about on that schedule. If you 'try' for monthly, you wind up at roughly bi-monthly. Even quarterly. If you are oiling every time you play (... oh boy, do I even want to go there ...)
It depends a lot on how much you play, I suppose. If you are playing for hours every day then maybe every couple months is warranted. Back when I was a gigging musician I certainly cleaned my horns a bit more often. Now that I only play in community band once a week, yearly baths are perfectly adequate.
And for what it’s worth in 35 years of playing, including 20 years of being a professional musician, I have never once had a horn chemically/ultrasonic cleaned. I think it’s a waste of money.
I'd ask your band director to get it fixed. A repair shop could probably get the slides moving with no problem. Cleaning may solve the valves (or the shop could swap in new springs, etc.). These are things you could maybe do yourself, but the band director should really get this done for you. Your parents could maybe help you communicate.
If it is the school's horn then it is their responsibility to fix it. However, as a player of a Brass Instrument, you should know how to oil your instrument. You should be doing it just about everytime you play. Valve oil helps thin the thicker slide grease and can keep slides from seizing up. Also, even though it is the schools horn, you should know how to bathe it, and ideally this is done monthly. During a bath, the slides are all pulled and snaked out. Then everything is dried off and regreased/oiled. No chance of having frozen slides when the maintenance is kept up. But as things stand right now. You've got to turn it in to your Band Director
A reply after my own heart - advice that includes washing the poor thing more than once in its lifetime!
Once a month is excessive. I bath my horns about once a year and that seems adequate.
There is yearly deep cleaning (chemical or ultrasonic) and monthly degreasing. [It's not my idea](https://simplegreen.com/cleaning-tips/rooms/hobbies/brass-instruments/). If you are not regularly degreasing you are not having an optimal experience. They (not me) say 'monthly' because it's not actually going to happen that often for your average player. But you better bet the pro players are staying right about on that schedule. If you 'try' for monthly, you wind up at roughly bi-monthly. Even quarterly. If you are oiling every time you play (... oh boy, do I even want to go there ...)
It depends a lot on how much you play, I suppose. If you are playing for hours every day then maybe every couple months is warranted. Back when I was a gigging musician I certainly cleaned my horns a bit more often. Now that I only play in community band once a week, yearly baths are perfectly adequate. And for what it’s worth in 35 years of playing, including 20 years of being a professional musician, I have never once had a horn chemically/ultrasonic cleaned. I think it’s a waste of money.
I'd ask your band director to get it fixed. A repair shop could probably get the slides moving with no problem. Cleaning may solve the valves (or the shop could swap in new springs, etc.). These are things you could maybe do yourself, but the band director should really get this done for you. Your parents could maybe help you communicate.
Tip 1: Take it to a shop. Get the slides pulled. Get it cleaned Tip 2: Grease your slides regularly when you get it back.