Cutie whatever you choose to do, make 2 separate backups of everything on your phone before doing anything else. SD card memories and USB stick memories, external drives, and computers can and do fail, sometimes earlier than you expect. 2 backups in 2 different memories has you covered.
Even then, if it's not all printed in hard copy, you don't really have it.
And if your new phone doesn't like any older files, you can convert them to what it does like, while keeping the original data and formats, without losing them.
Good luck.