Yes! You can swap out your current hard drive for a SSD. Just follow this IFIXIT guide: MacBook Pro 13" Unibody Mid 2012 Hard Drive Replacement.
As for memory you can do that as well. This system supports 16GB.
But before you go to crazy here do you really need 2TB of storage or even 16GB of RAM?
We do a lot of CADCAM stuff which is hard on both storage & memory. Currently our systems are mostly 1TB SSHD units and run mostly with 8GB (we do have a few 16GB systems). As the price of SSD's drop I'm sure we'll jump to them soon. As for memory unless someone is working on extra large drawings I think we'll stay at 8GB. I can see someone working on vids or picture editing needing more storage and RAM. Just food for thought.