@mauraulucien If I were to recommend a single ‘paid for’ resource it would be the Improvise for Real book by David Reed. The book totally transformed the way I perceive music, and their ear training materials have done wonders for my ear (I was starting from a point of havig believed I was tone deaf for nearly 60 years…).
The courses that IFR run make a lot of use of backing tracks, but they aren’t essential to the concept & I rarely use the tracks except for ear training & sometimes if I’m actually following a course. The courses are not essential (but they are fun & I’ve enjoyed them all). All the core ideas used by the courses are in the book,
The book is available in paper form from Amazon (https://www.amazon.co.uk/Improvise-Real-Complete-Method-Instruments/dp/0984686363/) , or in electronic form (PDF) direct from the IFR website (https://improviseforreal.com/).
They have lots of free stuff on youtube too.
I have no commercial connection with IFR, except that I’ve bought & used pretty much everything they offer & have been please with it all. 
I first came across David Reed & Improvise for Real over 5 years ago when I happened to come across this podcast. Maybe it would be a good starting point for you too?
I hope that is of interest & helps.