that is a quite often asked question and there is no anwser to it you will like as well.
artistic expression is not something which just comes to you. either you have it or not. ofte people do not want to accept that.
also artistic expression needs to be explored and develloped.
all the talk about concept etc is in my opinion just a construction of meaningless words.
there is only one rule: you have something to say or you do not have something to say.
and that will decide about the success of your project.
however sometimes you do something good without knowing it because what is in you is yet not discovered.
for new artists i think that is the biggest strugle. but one way might be to first sharped your craftmanship. the conceptual potention can only be develloped when you can controll the tool. so learn blender. find work that interests you, digital, or natural objects and recreate them. but for that you have to learn to see through analysing what you see and to decide how to replicate that.
thats a process of years unfortunately.
and to battle the artistic block there is one way to get out of it:
work produces work, it will you just have to accept the outcome!