I have built guitars with ash , maple, white oak, alder, mahogany, poplar, basswood, and even one using the softwood - yellow pine. I prefer to use poplar for a guitar with an opaque finish. Ash for clear finishes. Six or eight strings - this decision impacts the type of machine heads and magnetic pickup to be used. Type of magnetic pickup - pole piece pickups determine string spacing.
Shorter distances provide easier playing and less string tension.
Insure symmetry of the body shape. It is best to draw the curves on poster board for only one-half of the body along the longitudinal axis and then fold the poster board along that axis and cut the curves described. The shape is now transferred to the raw stock using the template. You should be able to buy everything else you need.