Use a notebook with lined paper (preferably) letter-size paper or smaller) and write down whatever thought you have. Anything that is unique to you or your family would qualify.

Don't use scenarios that are private in nature. Your friends and relatives may not like you after that.

Go to some comedy shows and study professional comedians.

You won't see the same routine, but it's a good idea to view them to get some insight on what you want to do.

Get to know some of them so that you can get your foot in the door.