IMO unless it was finished to a very smooth finish I would look at some kind of flooring on top of the concrete . We did vinyl plank with dri croe under it you could do core tec that has the underlaymnet attached. If you insist on painting that floor will need to be tottally spotless and degreased before any paint will stick. I would probably look at garage floor finishes

For all the reasons Patricia mentioned, I think painting it would be a mistake. I'd do either a tile floor or carpet tiles. Not a fan of LVT; I know it's popular but it's an ecological disaster.

"Paint and then seal"...sounds like using garage paint with a polyurethane sealant, is that correct?

Be VERY careful with concrete paint + sealer. They are OFTEN for OUTDOOR USE ONLY!!! There are TOO MANY people who made themselves sick (ill...as in move out of the house for 2 weeks type ill) because they used 'exterior grade' products inside their homes. And yes, a garage sealant/paint finish are exterior grade. Garages are not considered livable space.

Thank for the input