Thanks for your question, I am Sam and I am one of the UK tax experts here on Just Answer.
You should be filling in a self assessment tax return for HMRC each year, even with just this one property - so that when your income increases with rental income then your tax can be calculated for payment for each 31st Jan
Furthermore if you are not UK resident then your managing agent (or your tenants if there is no managing agent) should be deducting tax from the rents for HMRC and paying this over to them each quarter. Or you can apply for the non resdient landlord scheme - I have provided a link for information below
And as a non UK citizen you may not be entitled to UK personal allowances so in fact it may be all your rental income is liable to tax.
I have provided here
1) Link to register for self assessment
2) Details re the non resident landlord scheme and tax on rental income when not resident
3) Uk personal allowances and non UK citizens although this is the consultation document this provides the gist of eho continues to be due alloances when not resdient in the UK and not a UK citizen https://www.gov.uk/government/consultations/restricting-non-residents-entitlement-to-the-uk-personal-allowance/restricting-non-residents-entitlement-to-the-uk-personal-allowance
Let me know if I can assist or expand further