How to design a rating system correctly?

Question

Ratings

Good afternoon!
I want to do a rating for one sport (single) in the summer, I’m slowly thinking how.
I know how to program a little, but I don’t have enough knowledge on how to make tables correctly and how to calculate the rating, I ask for advice.
Input data: no more than 1-2 thousand athletes (no more than 256 in the tournament), the grid is a random olympian (that is, every round the opponents get "out of the hat").
I will have a table of athletes, tournaments, teams.
Questions: 3) Choosing a rating system. It seems to suit Elo, Glico. When is Elo or Glico better? It is clear that everything is googled, but if you have any advice or opinions, wishes, I will listen with pleasure. Thank you.
1) Where \ How to make the "move" of the tournament (Results, stages of the tournament). (There is a suspicion that new tables will be required, with data from several tables).
2) How to calculate the ratings of athletes (immediately after winning, or at the end, so to speak according to the protocol (because opponents are still randomly determined)).