Adrien,
I don't have any specific answers to your questions...just some thoughts
Buying land is not always the best option. a lease, either short or long term can get you access to land without the cost and potential liability included in owning land (as Eric mentioned the $1 per year lease) Many land owners get a tax break for agricultural production (in the US at least) so they lease land to someone to create a product and do it cheaply so their taxes drop significantly.
Basically, I suggest keeping your options open and looking at many ways to get going.
Another resource for this approach, specifically with animals are Greg Judy's books which can be found at his website
http://www.greenpasturesfarm.net/
Greg improves some parcels of land so much that the owners gave him a lifetime lease for free!
In the US we have a FarmLink program in many states.
Another option would be to partner with an aging farmer who already owns land and wants to see it improve and become more productive. This might allow you to manage a smaller system and get a taste of farming life before sinking a lot of money into it. it also means there will be some infrastructure already developed and you will often be improving land that has been disturbed by human use already rather than starting from 'scratch'.
From a business startup perspective, check out my reply to Ben's question regarding a Permaculture zone based approach to production.
https://permies.com/t/20151/financial-strategy/Permaculture-business-plan-templates
Getting ready to listen to Eric's podcast for more ideas on this and other financial strategies.
cheers,
Neil