The 19-year-old scrum-half was one of the stand-out performers as Wales reached the final in France.
He is now back in pre-season with the Scarlets and having made 25 previous appearances for the region Williams is aiming to nail down a regular place in the first team squad.
“It was a great experience. We had some disappointment in the Six Nations, losing to England in the final game,” said Williams.
“We had done so well but at the end of the day we had nothing to show for it. We wanted to push on and make an impression at the Junior World Championship.
“I’m just hoping to play more regularly for the Scarlets. I was quite disappointed with how much I played last season, so I want to improve on that.
“The previous year I played nearly 20 games for the club. I’d like to play more often this term and be more consistent in my rugby.
“I’m a confidence player and I will take confidence from the Junior World Championship. The under-20s group are playing catch-up with the others because they have been in for four weeks.
“We have had things to do in our time off, because the coaches expect us to hit the ground running and pick up the game-plan quickly. Hopefully, we can all push on and put ourselves in contention for selection quickly.”
But Williams knows he has is work cut out to nail down a starting spot with the west Wales region boasting a wealth of scrum-half talent.
Tavis Knoyle left Parc y Scarlets at the end of last season but Williams still faces fierce competition from Aled Davies and Gareth Davies.
“Gar and Aled have had four weeks more training,” added Williams.
“Last week was my first week back with the boys. Aled showed what he could do by gaining a place in Wales’s training squad last term and Gar showed what he could do with that immense try against Ulster in the Pro12 towards the end of the campaign.
“So it’s going to be very tough to get in to the match-day 23 let alone the side. We are all going to push throughout the season.
“Hopefully, I can come up with a few good performances, but whatever happens it’s going to be a position that’s really difficult to call. My aim is to play well and put my name in there.”