Hi Lesley, welcome to the forum.
First of all I would make an assessment as to whether they need feeding or not.
Difficult call to make if your first bees and on your own. Your location would help as different parts of the country are on different schedules. Oil seed rape is flowering in Essex/ Home counties..... in North Yorkshire it is about 4 inchs tall, we are weeks behind the south.
But essentially if the nuc is packed with bees and has a full frame of stores (honey) and lots of visible pollen and the weather is set fair I'd leave them to it, they will be okay on that for at least 2 weeks. You can make this decision at the time you transfer them into the hive. Check back in a weeks time and see if they still have plenty of stores or are they depleting what they have? If same amount of stores (or more) you made right decision. A very rough guide would be is the weather set fair....leave, bees can go foraging......is it going to pee down for 2 weeks....bees can't forage so will eat what is there.
The danger you can run into when feeding is knowing when to stop....the bees will usually take down every last bit of syrup you give them, to the extend they will store it and block any laying room for the queen.
If you do opt for a frame feeder, don't use the crappy wooden floats that come with them as a lot of bees will drown. I use a layer of cut down wine corks that seem to work.. Andrew will be fine for those
I must say I rarely feed when upgrading a Nuc to full hive, particularly in late spring through summer.....but do have a feeder ready in case you need it. You will need one for autumn feeding anyway.
Beekeeping is more about making judgemental decisions about what is going on in YOUR hives, rather than rote advice which, all to often, is not quite appropriate for a particular circumstance. Look and learn, it's not too difficult, although the plethora of conflicting advice makes it seem so.