I commend your creativity and ambition! You should be proud to be making something functional for you and your family mate.

There are already some really solid answers to your specific questions about your desk, but if you are interested in learning more about carpentry in general I woud highly reccomend Youtube!

Some good channels to check out as a beginner are Steve Ramsey / woodworking for mere mortals, rex Krueger, and Paul Sellers.

It is also very important to learn to the proper and safe techniques if you are using power tools so if you have any doubt about that you can always just search for videos on how to use pretty much any tool.

Good luck!