Clothing is a good bet. Someone who's more up to date on fashion trends may have better advice but button-ups are usually like $5-10 at thrift shops. Any color of plaid with the sleeves rolled up and the top 2 buttons undone is casual enough for most situations.

And if you can grow a beard but it's slightly patchy, see a barber or cosmetologist that does brow and hair fill-ins with henna. It'll be a little pricey the first time but ask and pay attention to how they apply it based on your needs then just buy the henna yourself. It's temporary, won't hurt your skin, and will get you through the next few years until you can grow a fuller one. It also helps to have it uniformly trimmed and 'edged up.' You'd think cutting it would make it look patchier but the trimming will prevent long wispy hairs accentuating the shortness of the patches and having it edged up will give better contrast against your skin.