Fortnite's creative maps are amazing, they let players build their own deathmatch levels, mini-games, amazing creations, and much more basically, players can build anything they can imagine.
But, the best way to utilize this feature is by practicing your aim, building, piece-control, etc for real games and arena matches. Creative maps can really help you to improve your skills in Fortnite, All you need to do is to find a creative map that this perfect for you and your skills and just play them regularly before real matches.
These are some of the best Fortnite create maps that can really help you improve your skills such as aim, movement, building, box fighting, etc
Raider's piece control practice map V3 (68186-9760-6633)
By RAIDER464
This creative map is the single best Fortnite practice map, It contains 25+ practice drills to improve your building and piece-control in Fortnite and it is also updated for chapter 3(with new weapons and sliding mechanics) and this creative map has infinite repetition so you can practice your skills again and again as much as you like or until you feel warmed up.
Raider's Solo Aim Trainer (6531-5731-1207)
By RAIDER464
This creative map is focused on aim training and it is also made by Rader464, he is an incredible Fortnite player with mindblowing Fortnite creative map-building skills so he knows what is important in training and improving your skills in real matches. This Fortnite creative map Is packed with some incredibly useful drills that will improve your aim and the best part is you can do it solo. This Fortnite creative map is one of the best and popular aim training maps gaming the players.
Finest's Realixmas(2v2)-Hype Reset (6570-5231-1418)
By Finest
This Fortnite creative map is not a training map but it is the best and realistic practice that you will get in creative with new weapons such as mk7, striker, and etc and it includes a ranking system so you match up with the players that are your level. This Fortnite creative map will train everything(aiming, tracking, building, piece-control, etc) against other players in real 1v1 or 2v2 fights. this creative map can really improve your skills without you repeating the same one or two drills over and over.
Good luck and have fun.