After downloading and signing into my microsoft account on the NEW launcher after being prompted by my OLD Java edition Launcher, I started the game and attempted to pull up my saved worlds I have been working on.  However after pressing Singleplayer  on the NEW launcher I was brought to a 'Create New World' screen and not the list of worlds I have on my computer.  I then checked my Multiplayer section and it was as if I had never joined any servers before in my life.  I didn't even check my Realms because I started to worry that I lost everything.  Checking my computer files I found all my worlds still intact along with their respective data.  I started the OLD Launcher and thankfully all my worlds, servers, and realms and data are still fine.