Maybe I'm misunderstanding you, but when you say that you 'can't see it', do you mean you don't know where it is up in the sky? You can't pick it out among all the other stars?

If you can't locate the Orion Nebula in about 10 seconds by walking outside and looking up, you are way over your head right now to be worrying about using a 300mm lens to photograph things.

You need to learn some basic astronomy. Learn where shit is, and then you'll never be lost looking up at the sky again.

You do that by sitting your butt down outside at night on a blanket with an app or a star guide book, and maybe some binoculars, and learn where stuff is.

I'm no expert, but I can look at any quadrant of the sky and pick out at least one asterism, enough so that I can hop over to the next star structure using an app, and then the next one, to locate something.

I know you must be frustrated right now to be able to find things! But the moment you know where Orion is, for instance, you can't help but see everything leap out at you the moment you tilt your head back and look skyward: there's his shoulder, his belt, his sword, and why, hello, M42! And no one can ever take that knowledge away from you.

Everyone here wants you to succeed, but you need some basic building blocks to do that.

Again, if I've misunderstood you, my apologies.