There are plenty of articles on university life etc. so I’m not going to repeat what they say. What I want to talk about is that feeling when you start a new job or even a new could that you have no idea what you’re doing and that you’re floundering. It’s entirely normal, I think it’s something that most people go through. When you start a new job the amount you have to learn is pretty substantial. You might be able to code well enough in C# but when someone hands you a 200,000 line project it’s going to take you some time to get your head around it, and I don’t mean a few hours. For a project that size it will take months before you’re fully up to speed with the code base.
Also, although you may know systems like TFS they way the new firm use it will probably be different. Even silly things like the fact that you won’t know their internal procedures very well so admin tasks will take longer meaning that you have less time available for development.
Many of the people around you might seem like they’re wizards in comparison to you but the reality is that they’re just further down the road with the code, the methodologies, the systems, the business and even things like they might have known the original developer so they might understand why some things are done they way they are.
This is especially true if you’re a new graduate or intern – the realities of software development are very different to the academic environment and it’s going to take you a while to adjust and to get up to speed with everything that’s going on. This is normal, don’t worry about it and do ask for help and advice when you feel unsure.
Be aware also of “impostor syndrome“. It’s pretty common in the world of art, music and comedy where artists are often confused by their success, not believing that they’re actually very good or deserve the attention they’re getting. From the people I talk to it seems fairly common in the computer science world too. If you’re feeling that you’ve somehow lucked your way into a position that you don’t really deserve or that you’re surviving not by a talent for developing software but by conning people into thinking that you’re doing a good job then this might be something that you need to be aware of.