Look at the vacancy ads and it will tell you what qualifications are required for each type of welding/fabrication post, I doubt repairing land rovers will carry much weight in the world of welding positions.
If you seriously want to be in the trade you have a long road ahead of you, competing against skilled persons with experience and qualifications.
Well sounds like you're prime canidate for tech.school go for a course 9 months to a year , go out looking for a job after completing course , take any position usaully helper or apprentice and learn the trade!!! in a year or two you'll be welding,,,or fabricating( fitting),,, hopefully,,,,,,,,,, good luck