Obelisk can. Ra can't be special summoned though.
Yes, unless the card itself or another card on the field says so, a monster can attack on the same turn it was Normal or Special Summoned.
Yes, you can attack with the Tribute Summoned monster unless a card effect tells it not to or it is after the Battle Phase.
yes, you can
Yes, that is allowed. You cannot, however, attack and then change to defense in the same turn.
Yes, if you control a monster in defense mode and it is changed to attack mode during the Battle Phase by a card effect, it can attack. The "Zero Gravity" Trap card is an example of a card that can switch your monsters' battle position during the Battle Phase. But if the monster already attacked that turn, was switched to defense mode, then changed to attack mode again by an effect, it cannot attack again on that same turn.
You just cant attack on the very first turn of the first person going. You can attack right after you summon a monster or set a card, or just attack if your not going to do those, as long as it is not the very first turn of the duel of the first person.
The Exploding Kittens attack card allows you to end your turn without drawing a card, forcing the next player to take two turns in a row.
You can attack with a monster and then tribute it in the same turn, yes. Obviously if you tribute it first, then it can't attack unless you've got a way to bring it back to the field.
If you are asking if "Five Headed Dragon" can attack the turn that it is Fusion Summoned, then yes, it can attack (unless the card used to summon it has an attack restriction on it). If you are talking about attacking on the very first turn of the duel, then no, "Five Headed Dragon", and any other monster, cannot attack.
Block Attack is a Normal Spell Card. Normal Spell Cards can only be activated in your own turn, in main phase 1 or 2.
Yes, generally you canBUT there are some cards that doesn't allow the effect to activate if you attack. Example is Chaos Sorcerer.so make sure to read the card text first.
"Mirror Force" is a card in the Yu-Gi-Oh! Trading Card Game. It is a Trap card can only be activated when your opponent attack with their monster on their turn. The effect of the card destroys all of your opponent's face-up attack position monsters. (It does not negate the attack, the attacking monster is destroyed and removed from the field so the attack simply "disappears.")