quick question about preparing TV shows

I know how to prepare the tv shows but have one question about the naming side.
if I have a tv show lets call it heroes for example if I was naming them it would be
Heroes S01 E01
Heroes S01 E02
Heroes S01 E03-E04
the last one being 2 episodes in one
but what if episode 5 had a part 1 and part 2 how would I name that for plex to be able to register it

many thanks in advance

contains almost all answers to your questions, including the multi-episode one:
https://support.plex.tv/hc/en-us/sections/200059498-Naming-and-Organizing-TV-Shows

no ‘space’ character between season and episode code!

The ‘Part 1 and Part 2’ question about ‘episode 5’ depends on whether it was originally aired in 2 parts or if it is just separated into 2 files. You can find that out too by looking it up on TheTVDB. If episode 5 is there only as one episode, then you have a “stacked” episode, which is also explained in the link above.

Here is the principal approach to naming tv shows:

  1. Look up your show on TheTVDB
  2. Take the title as it is used on TheTVDB. If there is something in parentheses, take that too. If the title contains invalid characters (depends on your file system), like § : % *, simply leave them out.
  3. Check the naming and the folder structure of your show. Name the top folder of the show exactly after the title on TheTVDB. No abbreviations. No additional subfolders. No aliases.
  4. Name the episode files according to the above linked naming guide. Use the same title as for the top folder. Show's Title - s01e01 - additional info.ext (’- additional info’ can be left out)
  5. After you corrected the naming and folder structure, perform the Plex Dance with all files for this show.

If you want to avoid multi-episode files or stacked episodes (because they have drawbacks)
here are possible ways to avoid them:

In cases where there are Two Episodes in one file I usually skip the E01-E02 convention and simply use the E01.
But mostly because it makes for better compatibility in media listings for other programs outside of Plex.
E02 is skipped in my listings but then again there is usually no reason to see E02 in a listing since it has no open and in many cases will simply play from the E01 start anyway.
The second Episode only exists contractually for syndication purposes.
The E02 is not needed unless your file is actually broken down into two file parts from a Syndicated version of the series.