Earlier quoted context omitted.
The career mode sucks. Feels too much like work. Use the free mode and build crazy rockets and jet planes. And have some fun. Going to other planets and orbital maneuvers are really end game stuff, which you can learn after getting tired of blowing things up.
I always tells noobs to skip career mode and do science mode. You don't have to manage money or kerbal lives, but you still get a sense of progression and value as you unlock new parts. You still have a purpose and a reason to go do things (i.e. collecting science), but it's much less complex and lets you focus on just having fun and exploring.
I like the science mode suggestion; gating off complex parts lowers the burden of choice, but without the financial pressure it's just "try this and learn to use it" rather than a race to unlock more powerful gear.