There's a direct references thread here and various analysis and symbolism threads here, but it probably wouldn't hurt to sit with a pen and paper through a four or five episodes and just note recurring motifs and symbols that stand out to you or resonate with you.

It's only fifty minutes, with others, on a panel, so my main advice is, as someone who does panels regularly, don't try to talk about too much, don't do too much homework. Fifty minutes of three to seven people talking about anything goes by faster than it seems it would.

My biggest advice isn't to load it with too much, as mentioned above.

I think stick to 3 or so *things* you want to talk about, and then leave the rest to guiding that discussion.

Even if it is just you, preparing a slideshow of photos and the 3 bullet points you wanna touch on with a brief bit of your commentary on each item and maybe how you derived that information, would be a great start.

This would be a general format I would use for your talk:

1) Introduce yourself: When you were introduced to Utena, brief sentence on why you like it so much
2) Introduce Utena: Some of your audience might just love Steven Universe or something, and not have as much context for what scenes you will be discussing so give a really really brief explanation of the show.
3) Introduce the 3 (or so) items you will be discussing at this pannel in brief.
    a) This cool scene in both of these animes-- why its important
    b) this crazy song that has a lot of symbolism
    c) This crazy theory about relationships
    d) ...
4) Discuss the first item in detail, limiting yourself to a time limit per section
    a) Discuss Item A
        i) Scene, Image or Clip?
    b) Discuss Item B....
    c) ...
5) Wrap up your conclusion of all of these items
6) Open to questions and discussions, but remember this is your panel! Drive the discussion
7) Close with a summary of what was discussed and provide resources for people to learn more


So, you asked where to start? its really important you limit down what you want to talk about, otherwise you won't fit it all in. I also think its important you isolate what shows you will be discussing. Saying something like "symbolism and influences" is pretty loaded... as an audience member, I would probably expect you to talk about something like "what is a prince?" or "why did they borrow the imagery of someone pulling a sword out of someone elses chest like Utena does" or... Remember that time in eva 3.33 when it was basically utena and anthy but shinji and rei?... Symbolism is pretty weighty (as we have this entire forum dedicated to discussing it) Influences can be a lot more simple to draw that line between.


I hope this helps and isnt information overload. What con will you be speaking at? would love to check it out! please let us know how ti goes.... and I hope you provide us the same information you provided your audience so we can discuss with you too!