I'm trying to get into smart card development using Java Card and I'm a little bit confused on which smart cards are suitable.
For example, if I were to order something like this (AliExpress Link), would it be suitable? What would I need to do with it before being able to upload applets?
No not all card understand java, the two major groups are:
The latter ones need an entirely different approach, since you don't load any code, but all is present as part of its operating system. So it boils down to "just add files, keys (and possibly other objects as well)".