What I think of when I think of the word Garden, I think of a cute little plot in england, or behind a log cabin. Why do I think that? I have no clue. I have always liked the quaint aspect of a garden, But yet the size of a large one is awe inspiring. When I decided to build a garden I started out small. The reason being, I did not want to overload myself. Often as gardeners we want to think so big that we become a small fish in a big pond, and are easily overhwlemed. There is no question that 300 square feet is easier to maintain than 3,000 square feet. But the truth is, it really isn't. I suggest starting a small garden first because it gets you used to the tasks that come along with a garden. Your attention is not being drawn on the garden as a whole, but more or less focused on each individual plant. The experience you will gain from this hands on experience will be beneficial to you and your garden since each plant gets the care it needs.
But what happens when you want to expand you garden?
Simple. Like I stated earlier with 300 square feet being no harder than 3,000 square feet. Once you know what each plant requires, and realize that each plant will react the same as the others, you can begin looking at the garden as a whole instead of each individual plant. Sure weeding becomes more tedious, BUT none the less is still the same amount of weeds per square foot as if it where 300. The fertilizing can be done in bulk, ammending can all be done at the same time, and watering can be done with a drip system. There is no doubt in my mind that when I went from a 300 square foot garden to a 3400 square foot garden that it was easier. It was easier because the needs of the plants are the same, and all you do is replicate on a larger scale. So if in the future I wanted to go to a 1 acre plot, I absolutely feel confident I could do so.
In conclusion, I would recommend starting smaller than you would feel comfortable with, because the tiny gardens are where you learn the basics, and the ins and outs of plant requirements, watering scheduals, analysing what nutrient deficiancies look like, and so on. It will better prepair you for a larger garden in the near future, and will set you up for more success in the garden as well.