"What would be a reasonable amount of land to start with if I only grew the veggies, berries and fruit? "......... That depends. Where in the world is that land located? What sort of climate? How is the soil fertility? What are the available resources? Where one person could produce an abundance of food on one acre, another person somewhere else could need 20 acres or more to do the same. Where one person may have great soil, great "in place" fertility, plenty of warmth and rain, another person may have none of that. So, it all depends.
By a bit of experience, what do you mean? My own wwoofer feels he has a bit of experience, but honestly, he'd starve if he tried to independently grow all his own food. He only has experience of growing in a good location where everything is already developed. He hasn't seen mass diseases, crop destruction due to insects, nor severe drought yet. Nor has he had to start up his own farm.
I'm not trying to discourage you, but on the contrary, I'm trying to encourage you to be realistic so that you may succeed. That said.....having no land and no money will make things more challenging. In my area, no land isn't a major obstacle as long as you have transportation. I've helped a few young people get introduced to landowners who are willing to allow others to temporarily use their land. One family has been very, very successful farming small plots here and there. After a few years they have already saved
enough money to have a down payment on their own 20 acres. Another couple are also farming multiple little pieces of land and are doing quite well.
The lack on money will be more challenging. It means that you may be spending a lot more time working than if you had some cash to buy things like a truckload of manure or
compost,
water for irrigation, piping or hoses, etc. Having to make do without a pick up truck, without small equipment, will take time away from actually working your crops. Lack of money also means that buying enough seeds may be difficult. And buying fruit trees may need budgeting.
Starting out with nothing can be done, but it takes a willingness to work long and hard, be resourceful, and live a simplistic lifestyle. Many a person in my area started out living in a tent or garden shed for one or several years while struggling to get started. They often started out with a small bit of land, made improvements, sold it and bought something better. I know several small farmers who bought & sold several pieces of land before finally getting their current farms. Those that were determined and disciplined generally succeeded.
If this is something you really want to do, I would suggest that you read and learn as much as possible. Then start out small, gradually getting bigger as you gain experience. It an be an exciting and grand experience!