Discord is a voice, video, and text communication service to talk and hang out with your friends and communities.
Sorry for the late response, I didn't see this for a while.
If you delete your account your phone number should go with it - no need to remove the phone number and then delete the account. I don't think there's any way to do as you describe, because when you remove the number and want to log in again, it wants you to add a phone number to verify you
It's okay! Better late than never.
If I do, though how long until I can use the phone number again?
Normally it takes 15 days at least, this is the cool down period where you can change your mind. Then iirc it's 2 more weeks tops before all your data is deleted, this happens automatically.
There's also the method of removing your phone number, and then logging out without adding a new one so you can add it to a new account, but this doesn't delete your old account.
I will add that random redditors claim wildly different things happen, so if you are in doubt I highly recommend sending Discord support a message via dis.gd/request