Second-hand purchases

Certainly, you can do that just as you would enter any other purchase.

If you made purchases from a private individual, you can select 'private individual' as the supplier. In that case, you will only need to enter the amount, without specifying whether it is exclusive or inclusive of VAT. This is because a private person from whom you purchase something second-hand will obviously not charge VAT, but simply the amount they want from the sale.