Im ready for grouting what to use?
Typically you use sanded grout for seams over 1/8&quot; and non-sanded for under. Any good quality grout will do the trick if you follow the on-package instructions. Regarding the spacers, you want to remove them mainly because they'll cause a gap or weak point in the seam that could cause the grout to fail prematurely. Try using an awl or small screwdriver to get under the spacers and pry them out.
That silicone caulk will be fine for corners and along tub edges, etc.and should come in varying colors but silicone, while waterproof, is difficult to work with. You may think it will be easier to use but it isn't - it's meant for small patch jobs and edge seams. I'd stick with the grout which is very simple and easy to use. Again just follow the directions and yes you will want to seal it afterwards. Grout isn't waterproof and only marginally water-resistant.