I'm not good with history, can you answer this for me?

Because she wasn't in line to the throne. It had nothing to do with Mary of Guise being French. You have to be born into the family to inherit the throne, and she only married into it. So the normal thing is that it passes to the late king's eldest son, or daughter if he has no surviving sons - as happened in this case.

Mary's mother, Mary of Guise was a 'Queen Consort'. That means that she was just the wife of a King and not Queen on her own right.

Mary, however, inherited the throne from her father, therefore she was a Queen Regnant.

Same with the current Queen Elizabeth II. When she passes over her son and not her husband would succeed her.

No she wasn't heir to the Scottish throne. She was the mother of six day old queen and was Scotland's regent until she died, then Marys half brother became regent until she retuned from France aged 18.

Beside the inheritance question , there was a spat going on over Henry VIII not being willing to take part in the Roman Catholics Pope's wars , so to stop the British being used as the popes toy soldiers , he invented the Church of England .

It all culminated in the spanish pawn Phillip II sending the Armada to invade England because we were "heretics" or some such nonsense , but all it succeeded in doing was ship wrecking well over half of the spanish ships and taking potatoes to Ireland .

She was a french princess,spared marriage to henry VIII, she married james V IN 1538,after james premature death in 1542 she took power beside james hamilton, earl of arran,and in 1554 replaced him as regent to to her 12 year old daughter mary( mary was in france at this time), in 1559 she was driven out of scotland by the Protestants leaders,and arran once again became regent for mary,she vowed to get her power back,but was struck down by a mystery illness and died in 1560.