Following on from my post (on 25.12.18) and in case anyone is confused about the difference in standard between an open World Championship and an age-group championship, in an open World Championship, there are qualifying standards that must be reached first. Here’s a link to those of the USA, for example:
www.usacycling.org/team-usa/track
In short, you will need to have won specific competitions to be eligible to compete. Even at the lower standard for qualification (Bronze) in terms of time for the women’s sprint, you need to have posted a time of 11.177 or faster. For men, the qualifying time (Bronze) is 9.964 or faster.
The women’s sprint results from the 2018 World Championships are here:
en.wikipedia.org/wiki/2018_UCI_Track_Cycling_World_Championships_–_Women%27s_sprint
The fastest time in qualifying was 10.645 (Stephanie Morton, Australia)
The men’s results from the 2018 World Championships are here:
en.wikipedia.org/wiki/2018_UCI_Track_Cycling_World_Championships_–_Men%27s_sprint
The fastest time in qualifying was 9.674 (Jeffrey Hoogland, Netherlands)