I work offshore and agree with your comments about paying for courses. I'm lucky to have a trade as an electrician but paid for all my courses myself. I invested almost 4k and applied for easily 200 jobs a month for 12 months, I avoided the hire and fire agency's although they are the best way to get a start. Polite persistence is the key, I worked ad-hoc for 14 months and at times it was very tough being away for 21 days and home for only 5 before away for another 18. My lucky break came earlier on this year, I now have a permanent contract and rotation with a major drilling company. It's taken over 3 years to get here but my point of saying this is that it can be done.
Without any trade behind you it's pointless doing a few electrical courses and looking for work (in general not just offshore) for offshore there are lots of other areas one example being rope access NDT work, or coatings and boasting work, inspection reports. Even a steward/catering position pays very well. Getting a start as a deck hand or rousti is very hard but being in Scotland helps, never say never.
The point to all my waffle is that you really can achieve anything but it doesn't happen overnight and takes a lot of dedication.
As for onshore work follow an interest and depending on your personal situation, become self employed? you certainly have age on your side and there is nothing wrong with wanting to better yourself in life.
I should also say aim to do a job doing something YOU like, I got stuck with a job working for a company that I grew to hate for way too long, it made me a bad person in the end. I genuinely have always been fascinated by offshore work and have loved every minuite of it, that really helps when you think I'll possibly be doing it for the rest of my working life.
