My Kitchen sink's faucet is loose at the base and when I turn it on it has very little water pressure. Makes it hard to wash dishes. Does anyone know what it could be? If it gets tightened will the water pressure come back or could it be two separate issues?

If it gets tightened will the water pressure come back or could it be two seperate issues? The two are not relateed. Let's tighten the faucet first. It will be a lot easier if you purchase a basin wrench, (see image). Get in the cabinet and see the two brass nuts securing the faucet Using your basin wrench get on one nut and turn it clockwise until it n snugs up. Have someone to keep the faucet lined up. Now tighten both nuts down tight.
As for your low pressure remove the aerator,(see image) from the spout and check 5the screens for trash. Does the water run better with the aerator off? Let me know, Tom