There’s varying points of tax efficiency to being a sole trader or a Ltd Co. depending on your turnover/profitability etc.
I recently helped a forumite offline with some info from Mrs Stoner Sr (accountant), the most useful of which in the absence of any other information about your business plans is to book a couple of hours with a local accountant to advise you on the optimum structure for your business based on your circumstances. You dont have to put them on retainer or anything, just a couple of hours at their chargeout rate, say £50 an hour for pure advice.
You may want to look at VAT registration, flat rate VAT as well as Ltd Co., PAYE, Sole Trader, emplyt the wife, other salaried income, other investment income, Divis etc.