Just moved into property and switched to my last energy provider from the current one in this new house. Should i ask for bill?

You can call and ask but they are almost certainly aware of the change and will send you a final bill in a few weeks, or so. Still, no harm in calling and asking just to make sure.

They will send a final bill when due.

You need to let them know the date you moved in so that they know to charge you only from that day. They will, almost certainly, ask you to read the meters and give them the reading so that they can bill the previous owner to that date. Then they will be charging you from that date.

Phone them or check their website.

You can call them if you want, but they will send you a final bill.

When you move into a new property, you notify the energy provider that you moved in on say 3 January, give them a meter reading on the same date. You will then be charged from 3 Jan.

YOU don't get a bill from the last provider at the house - that goes to the last person who lived there, who were supposed to have advised them that they moved out on such a date and give them a final meter reading

It is not uncommon for it to take a month or so to get your last bill.