(I'm Brazilian sorry for my bad english)
I'm new in the game and i want some tips. I got all the DBs for the first time and I summoned Shen-Ron but i want to summon him again! I know you can find DB's in weekend events but I don't know when they start or where they are! PLEASE SOMEONE HELP ME!

Wrong area as this isn't a guide, and to find out what event to get the DBs it sounds like it's Korean version that has the weekend events. So simply wait for the weekend or ask in the Korean section. If it's not that version you may have to search more for the times.