Park power is the likely culprit, unless something on the AC portion of the inside power circuits shorted while you were towing (Typically the refrigerator, microwave, power converter, and possibly the water heater). Quite a few things happen the instant you plug into external power, so it's hard to zero in on anything based on your description.
The basic rule to remember is that as voltage drops, current (in amps) increases. Increased current through the circuit breakers causes them to trip. So, knowing the *actual* voltage at the park plug is a critical bit of knowledge. The amperage (amps) will be zero until something is plugged in, so you can't really measure that directly. A simple volt-meter can give you an idea, but not the complete picture. I recommend one of the many surge protectors that also gives an indication of the power you're connecting to. Here's an example: https://www.campingworld.com/portabl...tectors-30-amp
The voltage at the plug before and after connecting is important and should fall between 110v and 120v give or take. I get nervous at anything below 110v if I'm using my A/C. The current (in amps) should be no more than 80% or 24 amps if you have a 30 Amp service. Even at 80% load, I personally think that's pushing it. Incorrect polarity won't cause your problem, so it's safe to ignore at first as you troubleshoot (probably).
To troubleshoot, I suggest turning off every single breaker, and then plugging in. If the park breaker blows, you know that you have an issue in your TT's wiring somewhere before it even gets to the TT's distribution box.
If it doesn't blow immediately, turn on the main breaker in your TT. Then, turn on each breaker one at a time until a breaker trips. That will narrow your search. Then you can decide how to proceed. (I can't help much here. There are too many possibilities). There are breakers for both the AC and the DC circuits. You really only need to turn off the AC breakers, but it can be hard to tell sometimes. In my XT200, I had 2 mis-marked breakers from the factory, so that's why I suggest EVERYTHING be turned off.
Breakers fail, but rarely. The insulation on internal wiring fails, but even more rarely unless something chews it or punctures it. Power Converters and batteries fail, but those wouldn't be my first suspect in your case.
Finally, be careful! Electricity travels at almost the speed of light, and those angry pixies in there can be very dangerous, very quickly. If you're not sure, don't touch anything. Even if you're positive that the power is off, check it with a meter. Electricity isn't magical or even mysterious, but it demands respect and some knowledge. Pay a professional if you're not sure.