The Florida Garden Railway Society (fgrs.org) serves the Orlando & Tampa area. check out their web site and get in contact with them. I’m certain there will be folks locally that will help you along the way to the garden train addiction.
You can also norton search/google/bing/yahoo search for local garden railroad clubs in the Orlando area.
Start up costs…ell thats a tricky one that depends greatly on how big a layout were you considering. How wide a diameter of curvature you have room for. Are you thinking narrow gauge or standard gauge. These are all major factors. Its hard to give info without knowing what your interest are.
There’s a tab under the GR logo at the top of the page that will give you good basic info and I agree with reading sites like mylargescale.com and largescalecentral.com are great sources of info.