You either draw them or you don't?
No can tell you how to draw something, and personally I hate copying tutorials.
Just start working on stuff, post it and see how that goes.
Usually try to work with an isometric line.
Otherwise you can use a straight 45 degree if you want to go with earthbound style.
Start with building blocks if you must, like lego.
Also notice the corner at the bottom, you can either try two pixels wide.
I'd advise using 3 pixels for the closest corner of a cube it's usually easier to work with.
Maybe start by making your computer desk? and then maybe your room and objects within it?
Always a good starting point to learn.
My first isometric attempts sucked.
These are all from 2005, I'm sure I can do better now.