where can i find a main entrance solid wood door, minimum 36", with a
heart shaped glass window.

These types of things are frequently custom-made, and may be somewhat
less expensive than you'd expect. Ask a local woodworker or builder
for references.

Go to a wood builder's shop or other place like that.You can also go
to home harware or homedepot or lansingbuildal. There are also some
web sites were you can get coustem made dors seach on a web browser
"coustem-made doors" or Coustem doors or doors