You can’t learn the entire engine and c++ in 3 days, its silly to say that 
Anyway you mentioned deleting assets and having crashes after that, getting 000000x errors and similar - you are accessing null data hence the crashes.
You can’t learn the entire engine and c++ in 3 days, its silly to say that Anyway you mentioned deleting assets and having crashes after that, getting 000000x errors and similar - you are accessing null data hence the crashes.