If you are just starting out I would start with a 25lb and a 35lb bell. You do not need to get anything fancy for now, the Amazon Cast Iron will do fine. When you progress you can get a 45lb bell and again an Amazon Cast Iron will do fine.
25lbs: https://amzn.to/4kwK45p
35lbs: https://amzn.to/4klXDo6
45lbs: https://amzn.to/4jsw0bX
When you have progressed pass 45lbs this is when I would invest in nicer bells. I like Lifeline and Rep.
Lifeline 53lbs: https://amzn.to/43IzeCb
Rep 53lbs (24kg): https://amzn.to/43Vkm4y
You can either start with buying 1 or go ahead and get 2, for double kettlebell work.
Rep 70lbs (32kg): https://amzn.to/45nN4MX
I’d go with Rep for the 70lb bell, it is a little cheaper than Lifeline but if you want your bells to match then stick with the brand you like. Again you can buy 1 or 2 70lbs, for farmer carries, and for eventual heavy double kettlebell work, but starting with just 1 70lb bell is fine too.