Get on a 9 hole or par 3 course and get going. There’s nothing like experience hitting the ball from the turf as opposed to just mats. You’ll also have to judge wind a bit and read greens putting so experience gained across a number of areas. Just relax and have fun though!
I’d say it helps to get the ball airborne consistently and be able to hit a club 140/150 yds consistently (May be not straight) and then you can get round without being too frustrated. Not essential though.
Then choose how to play; you could use a tee on every shot to begin with if that makes it easier, or drop by the green after a certain number of shots to get short game practice etc.
I’d also pick an evening when courses are normally quieter for first time out. Even better if you know someone who plays regularly to help guide you round.
If you're new to golf, and I'm assuming you are then don't spend stupid amounts on balls - something like the srixon distance £10 for 12 is fine. Saying that you can get dunlops from sports direct for £5.
Srixon Distance, the cheaper Slazenger balls from Sports Direct or Inesis balls from Decathlon will be fine to start out with.
The cheaper the better works at first as it’s likely you’ll lose plenty so it’ll just be a cost.
As a complete beginner just buy the cheapest balls, basically anything round! Once you are able to hit consistent shots you can start experimenting a bit. Look on the likes of eBay for Lake balls or pearl grade to get you started.