Regarding the screen, it seems like it is just a protective film you’re describing. It’s supposed to be removed.
As for charging, I’ve learned than not all chargers work with EMO skateboard. In my case two “new type” chargers with a USB-C socket don’t work, but the “old type” with standard USB work perfectly. I guess it’s not really about cables, but about charger. What type do you use?
As you tried a few different cables / different power boards / different wall sockets and also used the original charging cable as well in those different locations? and you don’t see a light flash on the skateboard, it could be that there might be a possible problem with your Skateboard itself.
Probably best to contact support and submit a support ticket, possibly take a video of how this as well so the support team can assist you further.
You can submit a support ticket on the following page:
In the meant time, there are a number of many different kinds of charging options you can use to test to see if EMO can start up, but you will need to purchase these from a store / Amazon etc. This is one that I’ve heard works well. (see link below)
Of course you shouldn’t need to be purchase this as the skateboard should be working, so as mentioned, I would recommended to reach out to support.