I have floor tiled two bathrooms in the house 12 years ago and they are fine,and having had the wall between the kitchen and dining room removed and with costs mounting I foolishly told the other half I would lay the tiles thinking I knew enough to get by but having wandered onto this site I am getting concerned I could make a crucial error.

Having started to remove the existing kitchen floor tiles the adhesive is proving very difficult to remove

1) Can I lay tiles over this?

2) In the dining area it was previously carpeted, should I prime the surface?

3) Best adhesive for 450x450 porcelain tiles?

Thanks in anticipation

Remove as much loose adhesive as possible, Prime the floor and lay a skim of self levelling compound over.
Adhesive wise it would depend what was readily available in your area. My choice would be Mapei Keraquick.

Oh and welcome.

all great advice above

welcome to the forum

Thanks for quick response, how thick/deep should the compound be?

You only need to cover the old adhesive but make sure what ever leveller you use it is suitable as in some will say from 3mm to 30mm etc and others will say 4mm down to feather edge.