Welcome! I'll attempt to answer some of your questions.

If it isn't secession, then what is it?
It is simply "a plan in which 20,000 or more liberty-oriented people will move to a single state of the U.S., where they may work within the political system to reduce the size and scope of government. " That's it really. What exactly will happen when we move is still up for debate.
Will we have state-built streets and zoning laws?
As with most things, it will be done in baby-steps. Changes in (read: removal of) zoning laws are high on many members' to-do lists. As for the roads, that may be a while.
How would we clean our water?
Given that utilities are currently implemented as government controlled monopolies, much like the roads, this will likely remain unchanged for a while. Ideally the water and purification system would be privately owned, though issues of competition need to be worked out.
Are we going to have traffic laws and cops to enforce them?
Yes on both counts, but with regard to traffic laws they should not be different from non-traffic laws, i.e. based on the initiaion or threat of force principle. Riding without a helmet is not an initiation nor threat of force, thus you should not be threated with jail or the deprivation of your property (fines) because of it.
What about an FDA to regulate food, drugs, and their labels?
I think most FSPers are focussed on changing state and local law before tackling the leviathan in D.C.
Wouldn't the poor stay poor in the new free state? They wouldn't have the money to get an education, and they would have to work below what would be minimum wage. What would prevent the return of worker exploitation and abuse that was common in 1900 America?
I am surprised one who is willing to join the FSP does not already know that the above is a fallacy. While there are many texts on the web that can explain this very well, I will make my own attempt:
There are two approaches, the ideologic and the economic.
Ideologically speaking, so long as no force nor fraud is being used in an interaction between two people, the government has no right to
initiate force by mandating or forbidding or altering the conditions of the interaction. You don't have to work for me, and I don't have to hire you. If you choose to work for me, and I choose to hire you, the conditions of that arrangement have to be agreed upon by both of us.
Now for the more complex economics:
The price of goods in a free market is determined naturally through a process of objective analysis. How much does a hamburger cost? Well, it costs no more than people are willing to pay, and no less than the maker is willing to sell it for. How much does an employee cost? no more than an employer is willing to pay, no less that the employee is willing to work.
Practically speaking, minimum wage laws only apply to jobs thay would otherwise pay less, the true value being determined by the free market. Break that balance by setting wages artificially high and employers must do one of three things:
1) Reduce Profit: All things being equal there is only a finite amount of profit available from which the government can forcibly transfer to the worker. Many small business barely make enough to stay open, thus minimum wage laws help kill off small business, thus tranferring purchases to large companies that can better absorb wage increases.
2) Raise prices: If the businessman's competitors also have to raise prices, and prices overall artificially rise above market value, then this has the effect of a hidden welfare tax.
3) Reduce costs: As with reducing profit, this is a limited option. Typically this is implemented by laying off workers and asking the rest to do more.
I pity the homeless man that is willing to work for $1/hour sweeping a storeroom floor, but is turned away because if the owner hires him, the owner could go to jail.