Porcelain New member, need some tiling advice please! - Tile Advice

[Deleted member 54220]

So it's my first ever time tiling and I'm using 25cmx25xm porcelain tiles. I'm tiling directly onto a concrete floor which is level but I'm not sure whether I need to prep the concrete first before applying the adhesive? Should I do this first and if so can anyone recommend a good primer for this? I've also purchased a ready mixed adhesive but I'm debating on sending it back due to using porcelain tiles on a concrete floor. Again, would someone be able to recommend a good adhesive that will bond the tiles to the concrete well. Any help would be much appreciated!