self employment ans wtc question.

Morning everyone, quick question, I tried calling hmrc but there is industrial action/no ones answering.

If I were to go self employed, do I need to guarantee to be earning and bringing in the equivellant to minimum wage? obviously my goal is to earn more than this but I am worried for the first couple of months I might not ahieve this.

I have been self employed before but earning a lot more, with no need to claim at all.