How can I get a lot of troops in few moments?

Troops need to be trained although you can do this quickly with speedups and instantly with diamonds. The only other way to get troops quickly is using alliance contribution points to buy Lvl 1 unit recruitment items in the alliance store. These will only give you level 1 troops though and you will need to promote them which takes time. (or diamonds/speedups) so it is only a small help.