Hi,
The first step to getting the right feedback for your pitch is to find the people who you think are qualified to comment in the field.
In terms of expertise, you should look for these:
-Previous experience / involvement in startups
-Experience or involvement in VC's or Seed Funds
-A startup mentor
-Someone who acts as a judge in demo days
-Knowledge of the principles that goes into creating a good pitch deck. (I would recommend the book by Jason Calacanis and the part about pitch decks)
-Domain expertise (specific to your domain is ideal but not the most important thing)
You can find these people in clarity.fm (I am one!) as on other platforms such as Upwork & Shapr as well.