There's a presser foot tension indicator on the front of the machine. It should be set at the top blue line for free-motion. When the hopping foot gets frozen-up, it can be terribly noisy. If you're at the top setting, and the foot gets really noisy, the spring on the foot needs to be cleaned-up and re-oiled. Or, adjust the presser foot tension to a lower setting.
Some of us like the feed dogs up and some of us like the feed dogs down. When they're up, it gives you a rhythm to work with.