Tinii, If you need practical experience to identify specific symptoms to get differential diagnosis of Lower Back Pain then for the practical component you'll need to take a course or request the help of other physios near you so you can view patients.
You can learn alot from textbooks of course - But there are alot of them.
I'v trained in McKenzie and have found it brilliant with back pain - though I accept that it isnt the only way to treat backs like the method would indicate. That said the courses are really good and can teach you alot about back pain and how to treat it - so see if the courses are run in your country by doing a google search and investigate that maybe.