How do I account for Input VAT for a new business that is not registered for VAT yet?

Hello Abaweja, 

Welcome to the Community page, 

So you have two options, you can turn the tax page on and then just add your vat number when you are registered and out the vat on the invoices or expenses then it will all show the info for you ready to submit when your ready too or you can leave the vat and just do an adjustment when you get your first vat return.