Yes, you are an Ensign; you are not "just an Ensign". I would encourage you not to refer to yourself as "just an Ensign" no more than you should say that your RPO is "just a Third Class". You earned your commission through whatever commissioning source you accessed from, it may not seem it as you are wearing those gold bars but it is pretty big achievement in the scheme of things - one many of your subordinates would gladly accept if offered the opportunity. You (likely) lack experience, which is fine and even expected -- but by the nature of your position in the Navy and in the military at large you have a great deal of responsibility and (believe it or not) authority. Of the roughly 1.5 million people in uniform you are senior to about 85% of them, this is not for you to power-trip on but if you are right now "just an Ensign" you may later consider yourself "just the OOD" or "just the Department Head" etc. and while even the CO has a boss, we all have responsibility for our spheres of influence and if you say or portray that you are "just an Ensign" you will in fact be just an Ensign.
You may one day find yourself in a situation where you become aware of someone doing something that is illegal - this person may be junior to you, may be a very experienced CPO or even senior to you . you may be directed to do something that is illegal, immoral or unethical. Before that day, take time now to ponder if you will say "I am just a [whatever]" and not do something about it or if you will remember what your responsibilities are. Gen Peter Pace tells a good story of how in Vietnam when one of his men was killed by a sniper & he (in a fit of anger and frustration) ordered an artillery strike on the village where the sniper fired from. His platoon sergeant instantly conveyed that the order was (morally / ethically) wrong; the artillery strike was called off and when the Marines swept the village they found a lot of women and children that would have been killed. That platoon sergeant was not "just a platoon sergeant."
Yes, by you saying you were "just an Ensign" I assume(d)/inferred that you are timid. Maybe you are not ... maybe you are ... I don't know; it is what I got based off of three words. I hope I am wrong. I will likely never run into you in the fleet but I hope you are not.
If you have time, I recommend that you read about Ensign John Parle or Second Lieutenant John Bobo who despite being "just an Ensign/Second Lieutenant" saved a lot of lives. I naïvely (based on world events) hope you or anyone never have to experience combat; it is cruel and unforgiving and your adversary will not care if you are experienced or not, if this is your first day on the job or if you have been there a year. You as an officer will be responsible for the lives of those people you lead ... regardless of if you are "just an Ensign" or promote before then. It is not a mindless Message to Garcia rant I am trying to put out here, it is more than that. My message: "Don't sell yourself short because of your rank", it is hopefully temporary and you will promote into positions of increased responsibility as time goes on. Make your mistakes now, but assertively make them ... make decisions; be in charge of your division, be in charge of your watch team or whatever you are placed in charge of; the people who are assigned to you will be better from it, your command will be better for it & you will be better from it.