Hi, and welcome to the forum.
Your choice depends on what you plan to use your drone for.
The Mini is a great entry to both new pilots but also to those who want a really small, portable aircraft but isn’t the best in windy environments. The
Air2 is more capable while still being very portable, handles wind far better and has a more robust radio system for control and video link back to the pilot.
Some people start with the Mini and upgrade later but many also start with the
Air2 and stay with that model for its performance, features and price.
Next up in the range are the larger
Mavic 2 Pro and Zoom around twice the price of the
Air2 but add further features, a larger more stable airframe and larger cameras.
All models are very easy to fly even for a complete novice.
If I were buying my first aircraft now it would certainly be an
Air2. I ‘bought’ my Mavic
2Pro entirely out of Qantas Frequent Flyer points so it was a no brainer.