Go over the trailer carefully checking all components are fitted correctly.
Fit the coupling and complete any wiring required for electric brakes.
Double check your spring hanger bolts and "U" bolts on the axle that they are secure and tight and the wheels to the trailer.
Hand tighten the stud nuts to help align the rim on the hub and tighten the nuts in sequence as below. Ideally use a torque wrench to ensure that the nuts are tightened adequately.
Torque Settings for wheel nuts are
7/16" UNF 110Nm or 80 Ftlbs
1/2" UNF 125Nm or 90 Ftlbs
Put a dab of grease on the towball and hook the trailer up to your tow vehicle and double check that all the lights are working.
Grab a new vehicle registration form from your local vehicle registration centre, fill it out and register your new trailer. Attach your new license plate to your trailer and book the trailer in for a Warrant of Fitness.
Once the trailer is warranted it is ready for loading!
For the first couple of outings with the trailer, take extra care to get used to the trailer and how it handles on the road.
Every trailer trails differently and getting a feel for how the trailer handles takes time.
Good luck and happy trailering!