Well, if you just got the parts you should use them and see if you like what you have.
Get some games and see if your GPU can play those games at 1080p 144hz. Games like PUBG, R6, LOL, and CSGO tend to have high fps (esports titles), but if you play games that are AAA titles, you might not get the performance you want. In that case, then look towards an upgrade!