Thank you TJ for the detailed advice. Regarding safety gear I have race suits, gloves, helmets etc from track days. Not sure if they are suitable for karting as karting seems closer to motorcycle, with scraping on the ground and multiple mid-speed impacts being the main concern, whereas auto-racing helmets are for hitting roll cage one time very hard.
I didn’t know rib injury was common, a simple search seems to suggest a lot of people have them. Hopefully, nothing permanent and I’ll definitely get a good rib protector.
I’m going to check out the tracks around my area on practice/race days to get an idea of what brand, setup and class people are doing.