Short answer
If you’re testing the waters with 1–2 machines, you can keep it simple: pick a basic structure (sole prop or single-member LLC), get paid cleanly (EIN + separate account), handle sales tax where required, and follow your state’s vending/weights & measures rules. You may not need micro-market licenses if you’re not running a micro market, and, as of 2025, most U.S.-created companies don't file BOI with FinCEN (foreign-formed companies registered in a U.S. state may still file — check the live FinCEN page).