The CDJ 850 although they don’t have hot cue’s you can set up to 8 memory points in rekordbox and use the cue/loop buttons to skip through them. So if you set a memory point when you want to start the mix you can call it up with a button press.
for me I hardly ever get to play anywhere where they have monitors so I beatmatch with bout songs in headphones then take of the headphones while mixing
with to much music you could start by only exporting song you know fairly well to USB and at to them as you get more familiar with the others.