Dude, I say go for it. I grew up playing basketball and just started playing indoor rec footy last year at 30. After playing at the back a couple seasons I switched to keeper. During some pickup games I gave it a try and the team captain said I should give it a go during regular season games. So you're already ahead of me on having played the game longer. Some games are pretty rough, lol, but I take it one clearance, one save, one distribution at a time. Every moment is a learning opportunity that you can build off of. You'll need a good mixture of humility, confidence, and self-forgiveness. If applicable, I suggest wearing a cup. It might only be needed once or twice a season, but you'll be thankful. Also, I've found these (link below) to help my knees from getting scraped up since I play on astroturf. I'll echo someone else's comments on watching video tutorials, I've found those to be helpful. Best of luck to ya!
https://www.amazon.com/dp/B077TJ9RM3?ref=ppx_pop_mob_ap_share