if my new router only has 2 LAN ports, and I buy a switch, can I just slap that badboy into one of the router's ports and use them like normal?

if my new router only has 2 LAN ports, and I buy a switch, can I just slap that badboy into one of the router's ports and use them like normal?
Short answer: Yes
Long answer: If you were in a situation in which the answer was no, you would already know. Depending on what kind of router it is, the two ports might already be switched behind one actual interface.