Hi this is my first home so I have no clue about anything. But for the past couple of days my condenser unit outside has been very noisy. The fan is still turning and there is still heat inside the house. It makes this noise like it's hitting something within the unit. Is this a sign of a major problem? Thanks in advance for your help..

Yes it could be a problem. It could be ice forming if it is a heat pump system running in heat mode. Might be best to have it checked out so as not to cause any more damage. It could also be a bad hub or otherwise a loose hub to motor connection.

Could also be a tree limb that fell into the outside condenser and the fan is hitting it, or a large dried leaf (s), or, God forbid, a little critter that crawled in to keep warm, when the fan was not running... (hope it isn't the latter)!