Creating u23 team and placing in a league.

[musicman]

Hello. My football club doesn't have an u23 team so I created one for my save. However I now need to place the team in an under 23 league. I want to place them in the u23 division 3 south and see if they will progress from there. How do I add them to the league and do I need to take another team out ? I also want to add them to the u23 cup structure as well if there is one. Also is it possible to be involved in their day to day coaching as well as managing the first team ?

Either that or I was thinking to have a B team and place them in the Isthmian south league if this is possible ? Again would would I have to remove a club. 

Thanks.