Rim suggestion

5 lug on 4.5" (114.3mm) is a pretty standard size.
Ford also uses this pattern, as well as Mopar and probably many others - under the metric size listing. backspace / offset will be a bigger concern in that size range, so you will need to determine that on your particular car, especially if looking at wheels for more modern cars which tend to not run as deep even if they are as wide.
You may have to consider bumping up /down/ adjust your desired rim size, as I dont think 17's are as popular as they maybe once were, so choices maybe limited in tires and wheel sets. Good luck though,
Great on you for building a car at such a young age, most kids are in front of thier Iphone or game console!