The contacts are in the phone and/or SIM as are text messages.
You may be able to copy everything form the old card to the new one (folders and files) and the apps still work. You'll want to do that for all the other files anyway.
The apps could be on the phone or the card. You should be able to check and move them (based on experience with other LG phones).
I'd try copying first, and if that doesn't work, then move the apps to the phone, swap cards, then move them back.