Take lessons. I cannot stress that enough. Take lessons from an experienced teacher. Most casual golfers have no problem taking their novice friends out and giving terrible, horrible, no-good, very bad advice. If a person hits an uncontrolled slice (like the vast majority of golfers) then that person has no business giving advice to anyone.
Buy used clubs and balls. A used set of quality clubs is much better than a new cheap (like Walmart quality) set. When you are just starting out, the quality of the ball you use really doesn’t matter so buying used balls is the way to go.
Spend a lot of time at driving/practice ranges before you ever go on a course. I would say at least ten visits to the range before trying out a real course. Someone who doesn’t know how to golf will just get frustrated on the course and can ruin the afternoon for potentially dozens of players behind them if the course is busy.