Is the meter in prepayment mode (i.e. you have to top it up before being able to use electricity)?
If not, then the figure you see is a calculation of the amount you owe since the start of the billing period. Since this is a new meter, you’re still in the first billing period and the amount is supposed to show what you currently owe. It is updated every second as regards consumption, with the standing charge added once each day.
It depends on the correct tariff having been loaded on to the meter; you should be able to find the active tariff rate by cycling through the menus. The tariff rates shown include VAT. Compare these to what you were told when the meter was exchanged; if they’re not the same (beware of the VAT!), Support can get them updated for you.
Have you had a look at your online account? This may not be fully working yet, so don’t be worried if some information is missing. It could take a few weeks for everything to fall into place.