How soon after an earlobe piercing can you start changing the jewelry?

This is pure anecdote, but I had mine first dine at 13. Excitedly tried changing it at 6 weeks and I vividly remember how painful it was, and I had to poke round for ages to find the path through. They deffo weren't healed enough at 6 weeks!

I would wait the minimum of 6 weeks and then if it doesn't seem inflamed you can start trying out different jewelry.

It depends on how much inflammation you get when you switch the piercings - you want to avoid anything that causes inflammation. If there is inflammation in response to trying different earrings, maybe put the posts back in and let it heal longer.

Spraying the site with sterile saline (like in the shower) is a good way to keep it clean and anecdotally it seemed to help bring down my inflammation - doing that once in the morning and once in the evening can really help.

I think it's important you clean your jewelry really well before putting it in (70% isopropyl alcohol does the trick).

Also make sure you're still wearing the post at night when you sleep so the hole doesn't close.

In those early days you might want to make sure the material of any jewelry you try on is hypoallergenic and safe for healing, ideally surgical steel or titanium. (Avoid brass, silver, or gold.)

EDIT: and my top advice would be to look up the best piercing place near you and give them a visit. If they're good, they should have lots of surgical steel and titanium pieces you can buy, and they should be able to answer your questions about jewelry that would be safe to wear while it's still healing, and they can look at your ears and make recommendations.

You're looking for a place where the piercers are all trained (bonus for medical training), licensed, and engaged in continuing education.

It’s hard to say. I usually wait 6 months before I change jewelry in a new piercing, but that might not be necessary. It doesn’t hurt to be patient with it. Though the urge to put in some cute jewelry can be quite tempting.

I'm a former body piercer (from, like, 25 years ago, but still). My suggestion would be waiting until you are no longer getting any discharge from the piercing site. After one month you should still be cleaning off dried lymph and serum from around your piercings. Until there has been nothing to clean off for at least a week straight, I would not recommend changing jewelry. While the fistula-the 'tube' of skin going through your earlobe--is forming, it's very delicate, and will be easily damaged by changing jewelry.

How long that takes is going to depend on your body; some people will heal very quickly, other very slowly. I don't recall that my ear lobes took more than a few months to fully heal. I have two piercings that I've had for decades now that still aren't fully healed, and probably never will.

As far as cleaning goes, saline or plain water and mild hand soap are your best bets. Alcohol, iodine, Hibiclens, hydrogen peroxide, etc. are all disinfectants, and will harm the piercing as it's trying to heal. (Hydrogen peroxide is no longer recommended for cleaning wounds, period.)

I went with plain gold rings immediately after piercing. The advice was to swab my lobes twice daily with alcohol, turning the rings then and only then. They healed pretty quickly with no fuss. I've pretty much stuck to pure gold rings since - turns out I'm allergic to nickel, very common metal for stud posts and keepers.