how exactly do i do that from a non Linux user?
Just run the command "top" in the command line and you will see how much memory and swap memory your system uses.
For your first question you could create an encrypted SWAP partition for extending memory and then delete it after you dont need it anymore.
The commands for this are cryptsetup,mount,mkswap and swapon but you need some Linux background to use them, check the man pages of them ("man mount" for example).
It should work like this:
Create a partition with gparted remember which partition you want to use (/dev/sdxx).
Then make as root in commandline:
cryptsetup -c aes-xts-plain -s 512 luksFormat /dev/sdxx
cryptsetup luksOpen /dev/sdxx swap
mkswap /dev/mapper/swap
swapon -U UUID
The UUID is the one of the encrypted partition but i forgot how to find it, perhaps someone else can help (or try swapon /dev/mapper/swap not sure if it works this way).