welcome to the forums,
Installing Linux on your computer is a simple and reasonably quick affair, you will need installation medium [usb or dvd drive depending on the age of your machine] a suitable distribution [based again on age but also specification]
If you want us to recommend a few suitable builds then pleas give us the specification [make model and any modifications] of your computer,
Please do not ask what is the best linux as this will be your choice based on what your main use will be and which YOU like the best, so be prepared to try out 6 or more builds to decide what is best for you.
Also be aware Linux is not windows so you will have a learning curve to contend with. if you have problems we will do our best to help