Making buttons can seem daunting, but it's really not. It's easy enough to make decent looking buttons using just your Google apps.
You have likely been using these types of basic drawing tools since your old Microsoft Word days, and Google Draw tools are just the same, if not easier!
The Cropping-mask tool is especially useful, particularly if you are using images off the net for your button (free to use). The mask tool allows you to crop an image into any autoshape, which can give your button the look you want (Square images are boring!).
However do keep in mind the age old advice
"Just because you can do something doesn't mean that you should "
- Jeff Goldblum, Jurassic Park
Here's a quick screencast to show you how easy it is, any questions just leave them below and I'll do my best to answer them.
- Don't forget to save your image as .PNG this way the background will stay transparent, rather than having a white background.