@SilverWolfAngel Monsters in Yu-Gi-Oh have levels. Levels 1-4 don't need tributes, so you can normal summon them instantly. Levels 5 and 6 need 1 tribute to normal summon. 7-9 need 2 tributes normally. 10-12, the highest, can't be normal summoned except for the God Cards Obelisk, Slifer, and The Winged Dragon of Ra.
You can only normal summon/set once per turn. Setting is when you play a card face-down. Tribute summoning/setting is treated as a normal summon/set. You have to send 1 or more monsters to the graveyard through tribute to tribute summon them, though. You can't tribute summon/set the turn you normal summoned though, and vice versa. You can Special Summon as much as you want though.