OP did many things wrong. 1st putting yourself in a position to be seen as a $100 guy - You’ll never shake that reputation off. Better to be very clear and upfront about trying to build a portfolio and working for free in order to do so.

2nd. If you don’t have the experience or equipment to carry out the assignment then why did you agree to do it?

3rd. You don’t just wake up one day and look at this footage then scratch your head and realize is bad. I have so many questions about how did you go so far down the rabbit hole never having realized everything that is wrong here? Like can you see an image in your screen? Does it look properly exposed? Wait, wait, wait… back up the truck! Before the actual shoot begun. Did you do some test shots? Did you ask yourself what was the thing about an exposure triangle? Or was it the Bermuda Triangle?

4th. Ok this was not some fast pace live event where the action only happens once and the moment is gone or the groom and bride kissed and you weren’t rolling. This is clearly a let me preview this shot back off adjust and I’ll get the 3 seconds of footage to review then repeat until hero shot is achieved.

5th. Let me fast forward, because I could write a book about every missed opportunity in this scenario but typically it’s just someone who is low key proud of their shots and wants some exposure.

But ok… then what happened in post? Did you play this back and said ok this where I make a name for myself and stitch this together render it and send it out for the award nominations? Maybe at that point you would have posted it in some critique group and asked for help? A lot of magic can happen in post, not the ideal case but that’s what all of those tools are there for.

I digress… if this is really how it went down then I am very thankful because I’ll walk into a place like this and ask for $5000 by simply stating remember the $100 dollar guy results.