In the image you can see i am starting with a list with three element, but if you look at the output its outputting 4, this is because i am using insert, when you use insert you need to define where you want the element to go and then the value to be placed in there, its a very simple concept to do and understand.

Next is count, this is as you would think, so in the () you enter a value that is in the list and it will output the count of all values, it wont add the elements, it just counts so you can see how many are there. Lastly we have clear which is self explanatory, it just clears the list