[Simple questions about editing and the editor - just ask in this thread]

Sorry if this has been asked before, but when creating a competition, what is the difference between 'Get all teams from division' and 'Get best teams from division'? It's a national cup so I want all teams in it but I've seen others use 'best teams'. 

[British league]

I'm trying to put together a British league with teams from England, Scotland, Wales and NI. My thinking is to try and convert the English system into British and add the other teams in, but I'm not exactly sure how to start this off? Or is there a better way I should be doing it?