Why might you want to set up your own community?
Safety, security and being in a nice environment with people you get on with may be the obvious answer to this, but alone is unlikely to motivate you to actually set up a new community, although may be sufficient to create a long queue of people who want to join once you have done the work in setting it up.
More likely the motivation to set up a new community will either be as a result of a problem, for example being mugged, burgled or having non stop vandalism, or as a planning measure preparing for your or a loved ones retirement or old age, or the long term needs of a special needs person or other you are committed to providing for. Another motive of course could be financial, perhaps you are looking for a way to create a large quality free home for yourself, or a group of you want to sell your expensive city property and move to a nicer country environment pocketing the proceeds.
The motivation is important. You should see a need and meet it, but also a direct benefit to you in doing all the hard work of setting it up. Therefore the start point is to be completely honest with yourself, why do you want to do this, why should you do it now, how are you going to benefit, and is it sufficient reward for the commitment you are taking on.
Next you need to consider the need you are going to meet, this is important as it will determine what sort of community, how it is set up and where it is located.
Is security a major factor, if so will it be walled in.
Is it for full time occupancy i.e. retirement or living or a holiday site.
Is it for able bodied or less able people, will ramps etc be needed.
What is the age range of residents, i.e. will they need a swimming pool, gym, bingo hall or all of them.
Is it to be a corporate site with let units or are people going to invest in their own homes, and if so what about reselling arrangements, and restrictions.
What are you expecting of the people who live there, is this realistic, and what about those who don't stick to your rules or ideals.
Are there legal problems in what you are proposing, i.e. racialist, sexist, or some other. You need to look at this in detail, several times projects we saw as solving one problem has been viewed an entirely different way by some other group.
Before moving any further you need to also look at how much time you can invest in this project, and if you have others who want to help you. Are they going to actually do what they undertake and will they jump ship when the problems start to come up.
Are you going to run this as a chief executive or are you going to form a committee, sharing the load but everything taking far longer, and possibly some of the ideals getting diluted along the way.