You're not going to get much for tracing ODBC / OLE DB failures honestly. Just today I helped trace an OLE DB failure where the root cause was an additional ; copied from the connection string for the password. The Engine > Service log basically just outputted what we already knew (that the connection failed).
In general the best logs are going to be in Server > Trace > System (e.g. Engine > Trace > System).
The page Gysbert mentioned above is quite good in getting you oriented to consuming Qlik Sense logs.
Are there other specific use cases that you have in mind?