I’m really sorry to hear what happened to your car. Many people charge batteries/ jumpstart cars the wrong way. The guard might have reversed the polarity.
I would start from the fuse boxes under the hood (there maybe more than one location). Check all fuses and relays. You should be able to test relays with a 9v battery and alligator clips and see if you can hear it work.
You have to diagnose this issue step by step. You won’t know if the critical systems are intact till you check the fuse box. Don’t forget that there are multiple fuse boxes inside the cabin too (under the dashboard on driver’s side and in some cars on passenger side too. See owners manual) . Check all.
If you cannot even hear a click from the starter, it is possible that the voltage is not reaching the starter motor. If you have a continuity tester, you can test the wires to see if they are damaged too. It is possible since you have multiple high amps fuses blown. After checking the fuses, diagnose the starter. With the ign key in start position, there should be about 10-11v on both terminals of the starter. If there is voltage on the starter but it won’t turn over, that is the first part to replace (assuming the wires are good). But, i highly doubt if your starter is affected.
Your best case scenario is that only the fuses are blown and you just have to replace them. This is the easiest and cheapest repair in your situation. Good luck.