I think you’re insane.
First, the face and neck are pretty delicate areas with coarse, dense hair (usually). It won’t be like waxing legs or a bikini line which both have generally sparse hair.
Second, with waxing, ingrown hairs are a problem. If your facial hair is the least bit curly, you could be looking at a horrible mess in four weeks. Make sure you exfoliate daily.
Third, even if you do go to a pro, some hairs will break before they get pulled out, meaning that you’ll still have some stubble in a few days which you’ll have to tweeze or wax again.
Fourth, your face will be swollen and riddled with tiny red pin-prick-like spots for at least a day. Make sure you take some Advil before you go.
I guess if you have fairly light, thin facial hair to begin with, it probably won’t be all that bad, but I still think you’re in for a world of pain.