Which Thinkpad for training and at home?

I would like to buy a used Thinkpad for my education and at home for Office / Netflix etc.

Budget up to 600 euro
15/16 inch screen
RAM and storage should be expandable
FullHD
not too loud and not too warm

I'm a bit overwhelmed when choosing all the models, which one would you recommend?

For 15 "a T series.

For 12.5 "/ 13" the X series.

With both the newest that fits your budget 😅