It will normally take five weeks for you to receive your first payment.
If you will not be able to manage your budget until the first payment, you can request an advanced payment of Universal Credit, but you will have to pay this back.
The repayments will be taken out of your later payments (you can request payments over the next twelve months). You can request an advance payment at the same time as you make your claim, via your online journal or via the Jobcentre.