JL
Cleaning the floor.
In the old days I would have recommended TSP (Tri Sodium Phosphate).

Heavy oil stains - paint thinner, naphta, mineral spirits to somewhat dissolve and loosen the stain. Followed by a clay kitty litter or clay absorbent material. Repeat as necessary. Leave the kitty litter dry outside.

Light oil stains, anti-freeze, brake fluid stains - make a slurry of powdered detergent and dish detergent. Let it set on the stain for a while. Scrape it up. Rinse. Repeat as necessary.

Muriatic acid wash - household muriatic (hydrochloric acid) is about 31% as you get it from most stores. I usually dilute it 1:10 for etching concrete. Some people go for a bit more dilute (1:20). Wear gloves and old clothes, rubber boots and possibly a Tyvek coverall. Rinse the floor afterwards to clean up any residual "flaking" of the concrete. The acid is neutralized by the cement in the concrete.