Welcome aboard!
There is however lots to learn so I suggest you work hard.
Each captain you fly with will have lots of tips, tricks and ideas that I am sure they will be more than happy to share with you (and if they don't, just ask). Stuff that they have figured out through trial and error over many years of flying. These are things you probably won't find in any text book or manual. I strongly suggest you write these down, it is an invaluable source of data.
Keep notes of any peculiarities regarding the airports you fly to as well. Not everything is in the approach plates. If you do this, then each airport will have less surprises when you visit them again, which makes your life easier.
I also suggest you write yourself a small checklist of all the non-flying related things you have to do in your job, and the order in which you do them. This could be anything from checking weather, getting load figures from ops, calculating duty times, calculating fuel and all the other paper work you have to do before/during/after flight. It is easy to forget things when you are tired.
And don't worry, nobody expects you to be 100% perfect just after line check, you never stop learning in this job.
The more confident you become, the more fun it gets!
Good luck with your new career!