Hiya,
First check that your Landy insurance allows you to tow a trailer (I'd be gobsmacked if it didn't), and that your driving license includes trailers (this is automatically included on older licenses, but if you passed your test recently you have to do a separate trailer test).
Though lots of people chance it with cardboard numberplates etc, you should really have a proper one made up. Most of the wee car parts places will be able to do that for you while you wait, but you need to take along the V5 registration documents these days before they're allowed to do it for you. A cheaper alternative is to mail order a
'replica plate' from Ebay, which to all intents and purposes will be fine as long as you choose a standard font etc.
How big / heavy is the trailer, and does it have its own brakes? Don't quote me on this, but I'm pretty sure a 110 can tow up to 3500kg braked and 750kg unbraked. I'm figuring (hoping) that if you're asking the question as a smallholder, you're probably not even approaching that sort of load though?
Also, be sure to check your electrics and brakes are good, and that there's enough rust left to securely join your towbar to the Landy, and the rear cross member to the rest of the chassis.