Many states require the bike to be registered as a motor vehicle. It's always best to get the title if available.
As for the bearings, to inspect, put the bike on a stand and grab the swingarm after the axle, try to move the swingarm side to side. Any play would show the bearing need to be addressed. Then check the front and rear tire by trying to move them side to side. Look at the hub when trying to move the tires looking for any play. Also look at the bearing in the rear suspension. Compress the suspension while looking at the linkage. Look for any abnormal movement in the linkage. Again any play would show the bearings need to be addressed.
Hope this helps, good luck