First of all, don't experiment. If you sit in your bedroom, playing around, the that is fine, but if you are doing something where you deliver your professional product (Theme) for a profession product (TV Show), then you should make sure that your song is not only musically great, but also perfect on the technical side (level, frequency response, misc. specs, etc.).
In that case, you should first start to LEARN the craft to some extend and not experiment and stumble over some stuff by accident. We are not talking about experimenting with a new effects plugin to get a specific sound, we are talking about delivery specs.
Your original question "Do I need to Master" is most likely based on all the hype on the Internet around "Mastering". Everybody is talking about, giving advice while it seems that 80% of that advice about mastering is utter bullish!t. The old excuse "Let's fix it in the mix" seems to have shifted to "Let's fix it in mastering"
Here is a simple advice: Forget about mastering and try to record/mix your song as good as possible. If you can't or don't know how to do it, then hire someone who can. You don't become a sound engineer by watching a few YouTube videos and buying a few Plugins. There is a little bit more to it.
About the Loudness Meter. There are a few comments from Lippeth where my red light would go off. If you want to learn bit more about Loudness Normalization and Loudness Meters, here is a tutorial I posted on my website.
http://logicprogem.com/Logic-Pro-X-Tutorials/Entries/2017/6/23_Loudness_Normaization.html
However, the good news is that in your case, you don't have to worry about Loudness Meter at all. The reason why there is no "Mastering" for music delivery for film/TV is because the music will go to the dubbing stage where it is only a part of a lot of other elements that are mixed together. That mixer has to know about Loudness Levels because that is nowadays the requirement for any broadcast/film delivery. Just make sure you deliver based on the required specs (i.e. 24bit, 48kHz, Stems yes/no, etc.). Your job (or the engineer you hire to take care of the mix) is to make your track sound as good as possible, based on what your client wants.
You always can play your track to a friend to make sure that it sounds ok and there is nothing that you overlooked. The last thing you want to end up with is to get a call from the dubbing stage and the engineer or producer complaining about some technical issues with your track.
Especially, if this is your first gig, you want to make sure to leave a good impression so hopefully they consider you for the next project. So don't blow 😉 it and good luck 👍.
Hope that helps,
Hope that helps,
Edgar Rothermich
Graphically Enhanced Manuals (GEM)
www.LogicProGEM.com
https://www.youtube.com/c/MusicTechExplained/
