The category would depend on the item itself, but generally a purchase invoice would only be raised if the business paid for it, or if it was owned by the business but paid for by the Sole Trader or Director. The tagging of the invoice itself would then be down to who paid for it etc., as per any other invoice.
The way you take money from the business depends on a few factors - are you a director of a company, or a sole trader; and if you are a director are you taking it via payroll or dividends? If you’re a director of a company, I think this is probably best discussed with your accountant as there are usually tax advantages depending on how you are paid.
If you’re a sole trader, there is no legal separation between you and your business, so you would need to simply withdraw the money from the business, log it in your current account and tag it as a transfer to the Proprietors Drawings Account. This would then need to journalled at a regular interval. There’s more on this here