I built one from scratch when I was younger (15), it was allot of fun and it made me look forward to coming to davening. (Metoch shelo lishma ba lishma…)
Don’t use plywood or pressed wood spend the extra money and use cedar or oak. Start with 1″ X 12″ and choose a length depending on if you are building a tabletop or floor shtender. Go to your local Home Depot and choose a nice board with no knots.
Use screws instead of nails to hold the wood together (it lasts longer). You may also want to drill a .25 in wide pilot hole about .25 inches deep before driving the screws. You’d be surprised how easy it is to fill the cavity with wood putty and sand it smooth before applying the primer and finish.
Let me know if you have any other questions.
Good Luck