Basic maintainance

Hello everyone, I am a long time lurker and first time poster. It might be some basic things but what I really need to know from experienced redditors of this sub is what to do beyond basic maintenance for someone who is willing to undertake tens of thousands kilometers a year. Frequency might vary for each part, I know that I should keep a good attention to engine and brake oil levels, having a clean oil filter, lights and sparkplug, tires and wheels, brakes, suspension, chain. But in case of a surprise inconvenience mid road, how can do a quick diagnostic, especially for every mechanical and electrical problem? And how can I identify if it's a mechanical or mechanical one? And do I have the possibility to improvise a solution to get me to the nearest repair shop? I can gess that some of you went through some, what did you do and how did you do it?