Choosing the right Apple Watch

As you know, there are several new models released (current models/in production). Namely - Apple Watch SE (2nd generation), Apple Watch Series 9, Apple Watch Ultra 2. From these models, how should I choose the right one for me? Which one will I like visually? What should I do about the reception? Or what should I focus my mind on to be able to choose the right model?

Also, as far as I know, the watch strap (loop) comes in three different sizes (Small, Medium, Large). How to choose the right size here? How should I measure it? Should I measure my wrist? what can I do?