I think that it is
invaluable to have linguistic knowledge before creating a conlang. But you can't become an expert in every field of study. So, no matter what, your language is gonna have some weak/unrealistic part(s). For example, I am fairly weak on phonology/phonetics and in syntax; that shows in my conlang. I'm trying to learn as much as I can in those fields in order to implement that knowledge in my conlangs, but it's difficult. I would say that, if you have enough patience, go ahead and start working on a conlang; if you wait until you have a totally solid understanding of linguistics, you'll be waiting forever
. But make sure you also study. Take a linguistics course (if there are none in your area, The Teaching Company has an excellent one [imho] ), and as you learn, change you conlang to make use of that knowledge. I think you'll be surprised how quickly your conlang morphs.
Also, remember: this is a con
lang. You can make it as realistic/unrealistic as you like. Just because some of us *glares at linguoboy* are obsessed with ultra-realistic ones, doesn't mean that you have to be.
Oh, and those questions aren't stupid
. I think every normal newcomer to the world of conlanging asks them. I know I did (almost made me stop conlanging
Does that help?