Going from ASP.NET to "classic" ASP is quite a step backward, but I guess I can answer your question.
1- frontpage will work but I highly recommend you just use notepad or notepad Plus. All you see is the code, but that's really all you have for "classic" ASP.
2- It might be a good idea to try to update to .NET (if you are more familiar with that) a page at a time.
3- If you really want to throw yourself into "classic" ASP, look up w3schools' tutorial, it touches all the bases very quickly.
Let me know if this helps.
Jared