You should grease the wheels after a long storage time. Old grease may have solidified, might have dirt in there to wear on the parts. Wheel greasing should be done yearly (on roller bearing hubs) if vehicle is used, twice a year if used often or over muddy ground, driven thru water often.
Wheel greasing is not difficult, just a bit messy. Wheels should NOT be rotated on the vehicle like automobile wheels. Antiques in particular may have worn enough that a wheel is “married” to that axle stub in it’s wear pattern.
Squeak is probably in the springs, but any squeaks should be found so lubrication can be applied to stop metal wear.
Driving Digest sells a good book by Dave Quist that covers vehicle maintenance and other carriage things, in an easy to understand manner.
Congratulations on your new vehicle!