I definitely agree with the previous posts. The ONLY reasons to compete at this point would be if you simply enjoy it regardless of the outcome, or if you want to start learning how your particular metabolism responds in contest prep.
I'd recommend that at your height, before you would compete, you have a lean body weight of AT LEAST your current weight, 225, and be no more than 250 total weight (i.e., no more than 10% body fat using calipers to measure).
And that would be for a novice show!
There's plenty of good info here on this board. But, you might also look up the posts by BigEvan23 and by JamerJay over on bb.com. Don't bother with the threads, just look up those two and read their posts and read their workout and nutrition information. Both are lifetime natural. Evan is 6'4" and Jay is 6'2", and I think there are things about both their physiques that you would like to equal and that will give you motivation as a tall person as to what can be achieved. Both are completely straightforward and honest in their posts and there's no B.S. about either one. Neither is a competitor, but I don't think that matters.
The good news for you is that I see nothing wrong with either your bone structure or the structure of your muscles. The proportions all look good; I see no place where you lack muscle tissue that can be developed, etc. So if developing your body is truly something you desire and you can put in the hard work and discipline, there's no reason you can't achieve something exceptional over the next few years.
Hope that helps!
Ken