I have been successful at epoxing concrete, here's what I learned.
Use 100% epoxies, you'll find them on line at cheapest prices. What you buy at the local home improvement store is likely 70% or so, diluted with a solvent to get better penetration into concrete but proper surface prep make that point moot.
The 2 most important things are prep and mixing. Wimp out on either and your not happy with the result.
Don't count on acid etching to do the trick. Acid etching is just more convenient but not near as good. Rent a diamond grinder. I rented a stand behind machine for $140 bucks. It is made to get all the way to the edges but won't get that tiny bit at the corners. I used plenty of water with it to keep the dust down and spent several hours running that noisy beast. I'd mask up and probably use that to get the tile up, with water.
Use the two pot method. Actually measure the components as you use them. Pour parts A and B into one pot and mix well, really well. Now, pour the contents of that pot into a second pot and mix well again. The first pot will have a bunch of unmixed polymer on the edges and that stuff will never harden. Leave it in pot one and accept some loss of material. Buy lots of those dispo buckets.
Holes and cracks in floor
If there are pock marks in your concrete deal with them as follows. Soap and water to as clean as possible. Then acid etch the hollows of the pock mark followed by good rinse. Take your epoxy and paint the holes for good adhesion then add fine sand to more epoxy to make a paste and fill the pock marks. Do multiple small batches if you have a lot to do. I used clean butter tubs for this. You can even over fill them and let harden for 24 hr. Now, diamond grind your floor and the epoxy you just added gets shaved to exact height of floor and will be invisible in the end.
Make some spikes
I just used liquid nails, a 1 x 4, and drywall screws. To some board roughly the size of my shoe and screwed short drywall screws through the board and then glued them to some discardable tennis shoes. This allows you to walk around on the wet epoxy and do things like throw those colorful sprinkles around and get thin spots etc.
I used a color base, then sprinkles, and then a clear epoxy over that. I then used a UV resistant polyeurathane over the top as epoxy will yellow under UV. Some prefer to use a colored 2nd coat and mix a bit of sand into to make it non slip as straight up epoxy is slippery when wet.
Feel free to ask if you have any questions.