Hi Mike - it's a real bummer to leave the forces after all those years to find you really have to start again from scratch. Have you researched any help which may be available through veteran support or similar?
The first thing I thought when I read your post was - "alpacas??", because alpacas are extremely expensive livestock to buy. As you have no funds you will need to set your sights lower than that, at least initially.
Have you heard of WWOOFS and HelpX ? With these schemes you offer to work on farms and smallholdings for a set number of hours per day, and in return you get free board and lodging. WWOOFS is British, and HelpX is world wide. With HelpX you can also do a wider variety of work, so as well as just learning how to run an Organic Farm, you can gain a much wider experience on all types of farms, gardens, ranches, big enterprises, small enterprises, and you can stay for a week, a month or a year, whatever you arrange. You must find your own travel expenses of course, but it is possible to live this way for minimal cost as you learn the realities of your dream, from people who are already living it.
You can find out more about these organisations by searching online - but be aware there is an unrelated HelpX site which if I recall correctly is rude
I can remember being at the same stage as you are, wondering how on earth you get into this business, but I do think that for you the HelpX or possibly WWOOFS route could be good.