Adam you sort your self employed Tax out by completing an annual Tax return either yourself or with the help of an Accountant or Tax adviser.

The revenue in good time might adjust your empolyed Tax code but that would be a long way off, so nothing to do now apart from inform the revenue once the business starts. I would avoid going limited until you are well established as the additional work is quite onerous. Once the business partnership has been established a few years you could tghink about 'selling' the entity to your own new Limited company as this may stablish a 'Directors loan' account which vastly reduces your Tax bill.

__________________
Been investing abroad a few years. Always amazed people invest in places that produce just a few months rent per year