Previous direct tv cable

I currently have direct tv and am switching over to Xfinity x1.  I am getting the self install kits but what else will I need. I have read that the splitters will need to be chnged out. To hook up 3 tv and internet do I need to get a 4 way spliiter? Do I need an amplifier? I am guessing that the cagle runs that are in the house now whould work with xfinity but is there any other dirty little secrets I need t know. Thanks