How to prepare and paint an old concrete porch?

[nonsibicunctis]

My house is on a sloping block that (face on) lowers from left to right nd back to front.

The front door opens onto a brick porch with concrete surface

The porch is approximately  1 metre high at the door end and 1.2m high at the other, with 3 steps leading up at the end to the roof of the garage, which used to be a deck but is now just roof.

The porch is approximately 1.5 metres wide by about 4 metres long + about a metre for the steps.

The house is about 55 years old and I believe that the porch is original and the paint on the concrete just as old. - In places there is virtually bare concrete but there are also areas where the paint seems relatively sound.

I don't want to acid etch if I can avoid it but neither do I want to do the job only to have the paint peel later.  However, as I have this mix of painted, reasonably smooth, (though thin) concrete patches with other rough bare concrete I'm not sure what to do.

Should I attempt to etch just the painted parts?

Is there a primer that I could simply put over the whole area?

Is there a coloured sealer that I could put over the whole area?

Any advice as to the best way to go, I would greatly appreciate.

[nonsibicunctis]

Thanks Eric.