there is no way to make a conventional interplanetary trip like creating an orbit and hope to get there
Actually, you can do that pretty well in Space Engine, I do it quite often. You can even use gravity assist, atmosphere breaking, orbiter-lander docking etc. However, it is not trivial to get to stable orbit or fly in planets' atmospheres, shuttle behaves according to atm. pressure and gravity and other things. SE is not far from physics simulator. There are a few good other games on market which you can use for training (I don't know if I can name here, KSP...). Flying ships in SE is very much fun and relaxation, it just needs some practice. Fortunately, joystick support is very good, it took me some time to set it up properly, but works just fine.