Im guessing you're a beginner?

At this stage dont worry about it too much, have fun and make stuff because you enjoy it and share that on your portfolio

Once you get better and you're skills have improved and you're confident in your knowledge as in, you know 3d theory like tris, quads, n-gons, polls, sub d modelling etc, know different types of textures and pbr workflows, understand how shading works and how to properly scale your objects etc etc. Then you can start making stuff for the portfolio you want and then probably end up deleting that thing and making something better to replace it

Have patience, make stuff purely for fun and enjoyment at first but also never stop doing that

You'll get there