There is a great initial course you should look out for called Beginners Property Secrets.
You learn many things with acronyms, such as.
CASTLED - The Goldmine Area Model
Cashflow - Buy something that has good cashflow. Aim for 12% yield
Amenities - buy something with good amenities such as, shops, train station, schools,hospitals and decent road links.
Supply - There has to be enough property stock to scale up
Tenant demand - to find this ask the letting agents (pretend to be a tenant) or check out websites such as Rightmove.
Local - close to you
Existing - it has to be something that you can walk in to. Victorian type houses are solid and lots of room height.
Discounts - You should be able to get a reduction in price.