He’s plenty old enough. You can go for it. Don’t rush it, don’t forcefully try to jerk him or anything crazy. Try to keep it as natural as possible. He has sexual urges and you want to teach him to see you as sexual partner, not just to fuck you. He should want to do it and he should love doing it. With that being said, not all dogs have a high sex drive. And some dogs learn faster or slower than others. So keep that in mind. He may instantly get the idea and starting mounting, or he may take a little warming up. Or he may not be interested at all.
As far as behavioral changes…that’s pretty vague. In his everyday normal behavior, he may be slightly more engaging with you. He may be a little closer to you. But you won’t likely see any changes there.
Sexually, depends on the dog. I personally have never had a dog that I had a sexual relationship with, my own dog or otherwise, attempt to mount anyone but me. I work with the dog to develop a real relationship beyond just sex. They don’t see me a just a hole to fuck. I’m a partner, sexual and otherwise. And they know they can express those urges with me, and we both enjoy it. And because of that, they don’t go around asking any human who walks in to fuck.
We have a show line GSD stud here. I co-own him but he doesn’t stay with me sadly. He loves to fuck. From the day he arrived from Germany, we had a bond, a real connection. Didn’t take long for him to start rather aggressively asking…more like demanding…to fuck. And we do it whenever we can. He has never attempted it with his owner or anyone else. And he never asks when I’m there but not alone. He’s too damn smart for that.
Anyway, long story short, focus on developing your sexual relationship with him, making him enjoy it as much if not more than you and worry about all the other stuff IF anytime arises. But I don’t foresee any issues. Have fun, be safe. Feel free to PM me if you have any questions.
