Hey, and welcome!
Modern jets are quite complex and intimidating at first, but once you get the hang of them they become quite intuitive. They're meant to be used by humans in stressful combat situations after all! :thumbup:
Personally, when in doubt, I'd recommend you to start with a slightly older and less advanced jet. The leap from WW2 to modern becomes more managable that way.
The L-39 is a very safe bet and has limited air to air and air to ground capabilities. It might become boring quite quickly though, so perhaps the F-5 is something to consider! Weapons wise it's only slightly