You need to be careful of over investing in one asset class. If you are a home owner, then you already have a significant part of your wealth invested in residential property. As pointed out above, interest relief on buy to let has been reduced to basic rate only as a transition to it not being allowable at all, making it quite likely that whilst you may make a gross profit, you'll still make a net loss if you have a mortgage to pay. Then there is the additional 3% stamp duty that is now payable on 2nd and subsequent properties. BTL landlords normally buy those type of properties which would otherwise appeal to first time buyers, but as hitherto they have been able to offset costs including mortgage interest, it hasn't been a level playing field, and it is clear that government is out to make BTL less appealing.
Then there are the practicalities. A single property is either let or it isn't, making "voids" a serious potential problem, as is the risk of getting a bad tenant who doesn't pay his rent. It will take you 3 or 4 months to get possession during which time you have no income and the overheads are the same. Add in the costs of insurance, maintenance etc and the reality is often a lot less appealing than the theory. When you want to sell, how long will that take? Do you sell with a tenant to give continuity of income, but reducing the pool of potential buyers, or do you get vacant possession and sit on a non-income producing asset whilst you wait for a buyer?
If you want to invest in property, I would suggest doing it via REITs (Real Estate Investment Trusts). These are companies that invest in property which is run by professionals, and by buying their shares you are investing in a large portfolio of properties, with variety of both type and location, reducing the risk of a single property with a single tenant in a single location. Buy these inside a SIPP or ISA and the income and growth is tax free, and currently an average tax free income of 5%, rising each year, with no hassle or overheads is not difficult to find, in addition to any capital growth from increases in the value of the property portfolio. And if you want to sell, your cash is just a click of a mouse away.
Self education is part of the price you have to pay, and I would suggest that a subscription to
"Moneyweek" would be money well spent. You need to avoid some of their more whacky ideas, but it'll keep you informed of current trends. You could do a lot worse than invest in their model Investment Trust or Lifetime wealth ETF portfolio.