Compiler Error 1046: Type was not found or was not a compile-time constant: Main.

there are/were no actionscript 1 components.  components were introduced with macromedia flash 5, not cs6.  they were called smart cliips, not components, back then and they could have been used in your fla. 

also, one of the first problems you're likely to encounter is that template was created using case-insensitive code.  ie, the template is so old the author could have (and probably did) write sloppy code like

var main = new Main(_root);

instead of

var main = new main(_root);

or vice-versa.

you should be able to search your library for Main using the library's search field

the search field is case-insensitve so searching for Main will also find main (and MAIN and the other 13 variants).

note:there may be no such object in your library.  but, if that's the case, there will be (or should be) a file named Main.as (or main.as etc) in the class path of your fla.  if that's been lost because you moved your fla from the directory where it was extracted (after downloading from monster.com), recheck that extract-directory or re-extract the files downloaded from monster.  and even is you have an object in your library with a usable name, you may still need the class file (Main.as etc).

p.s.  in my experience all flash templates are terrible.  this is an excerpt from Flash Game Development: In a Social, Mobile and 3D World​ in a chapter about writing problematic code:

Spreading code across more than one frame of a timeline and especially in more than one timeline is a time-wasting mess and strongly discouraged. Anyone who has ever worked on a Flash file with significant bits of code spread over more than one timeline more than a few weeks after creating that code understands the incredible amount of time that can be wasted looking for pertinent code.

The worst offenders that I have seen (and I have seen hundreds of problematic Flash projects), in the highly competitive worst Flash coding derby, are templates sold by websites like http://www.entheosweb.com/. Do not be fooled into thinking you can get a head-start on a project by starting with a web template offered for sale. There may be some well-coded templates sold online but I have never seen one.

It looks like another error has come up. It said that I had actionscript 1.0 code in the file and the components were removed. It is asking me to covert all 1.0 code/components to 3.0. the compiler errors are related to the following code for "Main"

var program:Main = new Main(MovieClip(root));

addChild(program);