Theres no way now I would invest £30k in a property (that's not to live in) now. I own one, I wouldn't do it again, especially with the Renters Reform bill coming in.
You need a minimum of 25% deposit for a BTL mortgage, and it's higher stamp duty, so by the time you have paid fees, etc, you're looking at a house worth 100k. In my northern area, that would buy you a 2/ small 3 bedroom property in the not so great area, bringing in £550-£600 a month, say £7k a year.
Tax on that would bring it down to £5.5k if you're a lower income earner. Any void periods reduce your turnover too.
Mortgage on that would be around £275 a month, if you're not an experienced landlord then £60 a month letting agent too. Insurances. So costs before any maintenance would be £4380-ish. (I appreciate some of this is an expense before tax, but still adds up).
Any maintenance would basically wipe out your profit.
Personally, I would be investing it in a stocks and shares ISA, in a global tracker, and trying to add extra to it every month. Let compound interest do it's job. I'm currently watching the Rebel Finance school stuff on Facebook/ YouTube, it's interesting and easy to learn.