Secondary employment overseas on Global Talent Visa

I am an EU citizen and have been working in the UK since October 2023 with a Global Talent Visa. I was offered secondary remote employment as an hourly employee for an AI company based in the USA. 1. Is there a minimum threshold beyond which I must report my income from this secondary employment to the tax agency or I should report everything? Is that the same as the 1,000GBP trading allowance? 2. When should I report my income in my tax report for income that can enter my account before the end of 2024? 3. Should I set up a personal company (as a self-employeed person) to justify working for the one in the USA or will I be considered an overseas employee? 4. If so, are there costs associated with setting up a personal company? 5. The payments will be made through PayPal to a UK account. Is that legal under UK law? 6. Will my tax rate be determined by the sum of my income from my primary and secondary employment or for each one of them separately? I would be grateful if you can provide any other information you deem important for this situation.

Hi Eleni,
Please refer to: 
Set up as a sole trader: step by step,
Expenses if you're self-employed and,
Self Assessment tax returns.
Thank you.