Grammar when i should use "on", "in" and "at" examples please

which diference between "as longer as" and "as well as" i want know when use each one and why?

UFC (Ultimate Fighting Championship) THE UFC, Actually is the sport with more fans in few years I know, the last UFC was UFC 190 Ronda Rousey Fought against Correira (i think wrote well) and that happened in Rio de janeiro Brasil the native land of Correira, it was very short just thirty five seconds take to Ronda knock Correira Out, really that was insane all the public in the arena goes crazy despite they're brazilians. that was the maint event , also the co-maint event was great in which fought Rua against Nogeira, Rua won by judge decision, I want to Nogeira wins but i think his age don't helped. Well, this is my second essay in Italki and I hope anybody who knows english help me to improve. thanks for reading :D

My country El salvador My little country El salvador has been called "pulgarcito de america" many people say that is a danger country , it is, but not how you believe, i mean, im still alive, just kidding, however is a really nice place has his charm, the tipic food is the pupusas very delicious i eats all time, the most important thing is the spirit of the people, worker, passionate and though we have someones problems with the public transport currently , we can take the issues and transform in a advantage, well that is a little description of my country i hope can continues with the description of my country. with your help i can improve my enssays. thanks for read :)