I agree that it is perfectly normal to feel the way you do right now. I would be worried if you didn't have concerns! I still do!
If you don't know something, ASK. Don't worry that you should should already know the answer, or that you will appear "stupid." It will make you a better nurse in the long run.
Also, I have found time management and prioritizing essential. When coming on day shift, I try to find out during report which residents are diabetic (they may need accuchecks & insulin before breakfast & lunch), how each person takes their pills, which residents leave the floor for meals (so I can be sure to give them meds before they leave), who has labs & appointments that day, who has IVs running, emergent conditions and so on. After a quick check on any emergent patients, I go for the diabetics & residents who leave the floor first. That way, I don't have to chase them all over the facility to give them what they need. If there's time, I'll flip through the treatment book and mark who needs what treatments. I also systemically mark off each resident on my list as I give them their meds, noting the ones I will need to return to later. ( Each nurse has their own way of noting this - I use a highlighter to block off only the room number if I need to return, or block off both the room number & the resident's name if I don't need to give them any more meds.) I then assist feeding, do charting, some treatments, etc. Then, I do my second pass, remaining treatments & charting.
Of course, the inevitable SNAFUs will through a monkey wrench in my system on a daily basis...falls, changes in condition, a barrage of orders, and so on, so I try to remain flexible.
I hope this helps!