Some good stuff already said, Keep a note book, PE study books...
This is how my career started.
My first job, I started out doing structural engineering for cranes (which was highly Code driven). There was a PE in the company but he was a couple states away, but he was a phone call away. I had to work hard and learn a lot quickly and I don’t regret it. There are a lot of books and information available, that can help you do things right. This was during the massive layoffs in 2008, removeing "redundancy" and overworking people is not good when safety is a factor. I quit this job on the advice of the company PE because I was definitely in over my head, phone calls and emails can only go so far.
My next job after that was doing structural engineering for an exempt field, for industrial facilities (machine, conveyor, vibrating equipment supports). My boss was the original designer of everything but he did not have an engineering degree. Nothing was "to Code" because the Code is a minimum set of requirements. The company had hired me to take their designs to the next level. There historic method was to look at other people’s structures, copy them, and make them "look good". When it was up in the field they typically worked just fine, and if there was any doubt, they "throw more steel at it". I did analysis’s of everything I worked on and found some structures had safety factors of >20. Their main problem was vibration control, so everything was way over built. In this particular field, failure was almost unavoidable (there was 40 USTon of consumable parts). They had plenty of structural failures and had learned from them, typically fatigue or wear related, which is massively complex, and was a fantastic experience for me. Because of this the sites were NOT accessible during operation so personal injury was not the concern of a failure. They were mostly concerned with down time and repairs. For maintenance LOTO to get in the plant took over an hour… This was great experience.
All this summed up in a nut shell. Can you design something that can get in the field and cause personal injury? My first job, something could have gotten out the door with a serious error.
My second job, I had a very experience boss, and there were a lot of checks, and workflow that made failure manageable. They never had personal injury because of a design flaw or failure. This experience really propelled my career, because I got to see lots of complex failures and problems.
Hope this helps
Good luck.