Hello!!!
I want to ask how to mine bitcoin for newbie like me ??

Mining is not an easy job you need to wait for a couple of days i guess before earning a little big money. There are two ways or method in order for you to mine.
1. Mining using your computer - You can mine using your computer however you really need a good computer in order to mine fast or i should say a good specs in order to mine fast.
ADVANTAGES: You don't need to pay in order to mine.
DISADAVNTAGES: You'll be using your computer for a long time it's either going to over heat if it doesn't have a ventelation cooler plus you need to pay for the electricity.
2. Cloud Mining - There are a lot of sites out there offering this kind of service so what is cloud mining? It is a service where you can mine without using your own computer or mine even offline.
So how does it work? First in order to use their service you need to pay them or rent their computer they have diff list for example 5x faster mining = 50$ for 1 year you can mine but it depends on what kind of contract youre going to chose.
ADVANTAGES: You can earn even when you're sleeping, your computer will not be tortured and you don't need to pay high because of the electricity bill.
DISADVANTAGES: You need to pay for a contract (It depends on what you've chosesn. The faster the mining the higher the rent is) and it's a bit expensive