You haven't said what you're interested in most. If it's domestic animals, then look into dog grooming or training. Even a stables - farrier(I heard this pays a lot!), horse trainer, stable hand, riding instructor, etc. If it's rescue animals in the charity sector, pay won't be so high.

If you want to work with captive wild animals, then you have native species at a rehabilitation clinic or exotic species at a zoo. Both of these will require a LOT of experience, and neither will pay too well.

There's also animal technician work in a lab, yes you will be looking after animals used in experiments - but agree with it or not, those animals need the best care you can possibly give, and that industry needs people who care for animals to look out for them. From looking at job listings in the UK, it seems to pay a bit better than zoo work at the entry level.

There's also animal welfare inspector type work, and whatever your countries equivalent of the RSPCA is. This work would be hard and upsetting, and you would see a lot of horrible cases.

When it comes to schooling, dog grooming may require the least - you can usually take a short course in this. I don't advise training unless you know a lot about it, as there's a lot of misinformation when it comes to training dogs. Possibly shelter work would require little schooling, but would likely mean several years of volunteering in that shelter before being offered paid work.

The rest would likely require degrees or qualifications that will take some years to achieve. There are routes through, IF you are lucky, by volunteering at the right places for several years, but don't count on it. Check what is available in your country when it comes to animal based qualifications.