Hi:
There are no internal expansion slots to add any kind of internal cards.
https://support.hp.com/us-en/document/c04411700
To add wireless networking capability to your PC, you would need to purchase an external dual band wireless AC adapter.
Memory:
You can install 2 x 4 GB of PC3L-1333 memory. That is PC3L-10600 (1.35V) memory.
Your PC uses the same kind of memory used in notebook PC's.
This memory would probably work just fine for your PC...
https://www.newegg.com/Product/Product.aspx?Item=9SIAD8U8ER3458
There are dozens of models of external USB AC wifi adapters, so find the one that best meets your needs and budget.