Maybe makes sense to wait until Android V will be available? Its first Developer preview is scheduled for Feb 15
It will be aimed at developers, so it will not give us the full picture of Android 15 and will probably be unstable and full of bugs. Those interested in getting it, including users who are not developers, will have to flash the system image on their phone using their computer.
If you don’t want to go that route, you should wait for the first public beta, which should arrive sometime in April, or wait for the final release, which is the sanest thing to do if you can’t stand bugs or don’t want the risk of broken features.