Hi, and welcome to DT!
This thread looks pretty old, but it seems like it's been resurrected a few times in the past. Just a little advice, if you have a question you might want to start a new thread instead of adding to one that was last commented on years ago.
To answer your first question, you don't actually teach a dog to lift his leg when he urinates. It's one of those things that comes with age, if at all! When I was a kid, we had a German shepherd who never lifted his leg. He was a squatter his entire life. I'm not sure if that was due to his being neutered (I couldn't tell you what age he was neutered. If I had to take a genuine guess, I'd say... maybe 5 or 6 months?) or if he just preferred squatting.
My current dog lifts his leg, and he is also neutered, but he was neutered at 13 months. But even so, even though I don't recall exactly when he started lifting his leg, it wasn't at or before 4 months old. I can pretty confidently say it wasn't until maybe (and I'm guessing again here because I can't remember!) 8 or 9 months old that Zeus started lifting his leg, and it wasn't all the time. Sometimes he lifted, sometimes he squatted. It wasn't until after age 1 that he consistently lifted his leg up.
To your second post, yes potty training is definitely important! It wasn't too hard training my doberman to go outside. He even learned to ring a bell when he needed to go out! But we stopped using the bell after a few months because he started abusing it and would ring it just so he could go outside and play instead of pottying. Dobermans are too smart for their own good!