Just Joined

Hi all, like the site and forums so have joined hoping to learn more.
I have been strumming for about 30 years mainly until recently rythm on a 12 string as i like the sound.
I own 3 guitars at present a 12 string jumbo Accoustic made by Marlin which has now matured after 20 years and sounds really nice ( when played well ) My favourite guitar is an Epiphone Wildkat Semi-Accoustic ( Les Paul size ) great guitar. and have recently added a Takemine EG128SC Spanish Electro Accoustic so i can practice without the plectrum (Finger Pick etc) I use these unplugged and also plugged into a Laney A1 60 watt Accoustic Amp.
I also use a few effects tools KORG ampworks, Line 6 Pod 2, and a Zoom GFX 707.
I also have a few Microphones and have been know to sing along to my strumming.
Interests are based around the later sixties Beatles, Elvis, Creedance Clearwater Revival, through Heavy Rock Free Deep Purple etc but I like many types of music and can play most (To a fashion)
Although I have been strumming for many years I have a lot to learn and now have taken Semi-Retirement can put in more time.
I have no idea on reading music, scales or any of that stuff but have reached a point where i need to progress and to do so will need to learn some of the basics.
I want to venture in to using MP3 backing tracks to support my Guitar and Voice but know nothing about this area other tahn the tracks cost money to buy / download.
Glad to join you all.