hi Fish40, take a look at the last few posts in the knowledgebase sticky. The biggest improvement IMHO for CFS3 in recent times has been the development of a new shader package by Ankor. This updates the look of any install you choose to use. There is installation guidance by Majormagee towards the end of the sticky.
The quickest way to get started is to set up ETO 1.50, with the latest shaders (February 2017?). ETO already has a greatly improved scenery package, shaders, scenery and texture budgets ifles, and Av History v4.0 flight models so its a great start. Lots of aircraft and missions. One of the best things about the shaders is a tweak to an .ini file which means you don't have to re-run cfs3config every time you make changes to your install. This saves a lot of grief.
Get your head around the ETO eraswapper and how it works, this is the source of the most threads when people's ETO installs get corrupt.
Other packages which are good from the word go are the PTO Rising Sun package (again with complicated eraswapping bat files which take some time to tweak properly), and MAW which looks splendid with the new shaders, has recently upgraded terrain textures, and has lots of missions out of the box. The quickest instal and arguably therefore the most fun, is Pat Pattles BoB.
The thing about all these packages is you don't need to scratch around like in the past, updating textures, effects.xml, adding new sounds, shaders.xml etc. All that work has already been done.
One trap for young players that I recently found is that when I added some AvHistory planes to MAW, the stock effects.xml and associated fxtextures (for tracers, etc) did not contain a lot of the effects needed for the latest set of AvHistory weapons. Hence I was missing out on tracer effects etc.
Anyway all the best I hope you can find the time to do this old sim some justice - it truly is a different beast from CFS3.