I want to buy a small house to rent out if its a good price, even If I dont rent I can live in it, right time?

Is now a good time to buy a small house im 25 years old and was looking, i was also looking in London zone 4 if anyone has information on that part of London, but I was looking in the midlands like derby or Leicester for a decent house and even give it on rent. Ive only lived in the UK for about 5 years and I want to get a self-cert-mortgage that I dont have to declare my earnings, I can put about 20,000 deposit, any information appreciated, and God bless