gas is about as simple as it gets, a little spray bottle with soapy water is great for finding leaks if that is what scares you (in old days plumbers used to use a lighter on the joints, if tiny blue flame is dancing on it, it is leaking). most common fix when pilot won't stay lit is a $10 thermocouple at home depot which takes a screwdriver and wrench to change. 10 minute job and does not require breaking into the gas line. then you have the thermistors which are also like $10 which are also easy to change. you can even get the whole valve assemblies which are like $50 new and pretty easy to change. If the tank isn't leaking from rot, i fix it.
oil is a little stinkier, but still pretty easy to work on. 220, just be careful, trip the breaker, use voltmeter to make sure you tripped correct breaker, then ground out the leads in case capacitance has built up.
if you fix your own cars, this stuff is much easier in comparison.