Split Year Treatment Questions

Hi, I arrived in UK on 8 Oct 2022 and I have been working as an individual freelancer for my oversea clients. Few questions I want to clarify before I file my tax return: - I asked HMRC on phone before and they said for my case I don't have to submit a Self Assessment for 2022-2023, so how come I have to file a tax return? - If I still need to file a tax return, in the forms shall I enter the amount of incomes and expenses that I have after I arrived UK? - All of my income are in foreign curreny, how shall I convert them to GBP in the form? Thank you!

Hi Ho Chi Ng,
If tax resident in 22/23 you need to declare the income and as its foreign income, a tax return is required.
Please see guidance here: 
Tax on foreign income
For the exchange rates, refer to:
Exchange rates from HMRC in CSV and XML format
Thank you.