Get some old cues,
Practice -replacing tips, replacing ferrules, repinning,rejointing, wraps etc.
Cut some in half / section them and see how the are made up.
Learn what you like about the way it is built and how you would do it.
Can you make it that way?
Can you make it better?
Can you get the points even?
ETC ETC etc.
Old stuff cost little and you can learn alot.
You will learn more by making 3 cues wrong than being on the net and just asking questions.
Wrong can be, not straight, incorrect weight, balance point not in the designed or desired place,flaws in the finish, bad wrap, wrapgroove too deep/shallow, joint diameter too big ,too small.Pin not true,does not play well, handle rattles or buzzes after 1 year of regular play, et etc etc.
There again, you might make perfect cues 1st time out. You won't know untill you try.
You also have to decide the type of cues you want to be making and the market you want to be in. Do you want to have fancy inlays etc or other types of cues.
Been some good advice here as well.