Something mentioned in passing here, but is worth spending more time discussing is the neck. It’s a rather precise part for a first time builder and it need to be built correctly in order to handle the string forces. The materials, glue, tolerances, all of it plays a part and needs to be done correctly. You have to consider things like: do I want this neck to be repairable? If so, you need to use hide glue to install the fretboard.
If you’re not planning to get deep into guitar building, it might not be worth spending the money to invest in expensive tools and jigs for correctly setting up a neck, which means your best bet would be buying a neck. Allparts is a good suggestion, Warmoth and USACG are also good. If budget is a major concern you can probably get a usable neck from GuitarFetish or look on Ebay for a Mexican Fender neck (or a Squire for that matter).
Regardless of how the neck is built, it will still need to be set up with the guitar to have a playable instrument. This is not an easy process for a new builder (even myself, having built ~5 instruments still struggle to get what I want) due to the micron tolerances required.
Setup will include, aligning the neck and bridge, leveling and crowning the frets, cutting the nut, and adjusting the bridge intonation.
I don’t mean this to discourage you, it’s just a warning that there is high complexity ahead! If you’re not comfortable with investing the time and money to do these things, I would suggest buying a neck and bringing the finished guitar to a shop for a setup, should cost $100-$200.