tax questions

im wanting to go into djing full-time, doing bars and clubs and events but i'm clueless about tax. i know some of you guys on here are professional djs so could you help?

i figure that the tax people will turn a blind eye to people earning a certain amount but if i start earning thousands per week then i'd have to pay it then wouldnt i? or could i get away with it?

would i need to set up a ltd company to deal with this?

if i did this and started paying tax would it be backdated so i'd have to pay tax on the money ive earned from djing over the past few years?

is the amount of tax i pay different if i still work part-time doing a dayjob?

what are some cunning ways i can pay less tax or offset stuff against tax?

thanks!
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