Probably too late now, but might have been better to get calf gentle first in a small pen with no halter. When he is gentle enough to put the halter on without roping and choking him down or having to use the gate mash method or the squeeze chute or some other means of restraint, then he is ready for a halter. Once the halter is on, work on leading - one small step at a time and rewarding the calf with release of pressure and some combing so that he figures out how to lead - can even use a treat like you would training dogs. Do not fight with the calf if he tries to run off - work in a small pen and pretend your lead rope is about 8 lb. test fishing line. If he makes a run, let out some lead line and then reel him back in. Reward him when he makes a step forward until he can put several steps together. It doesn't take but maybe a couple of 15 minute sessions to get them to lead. Do not tie until the calf figures out how to lead. If he knows how to lead and likes people, he won't have much reason to pull back. Do not tie them high until they are broke to tie and stand normally.
If you halter them and tie them up when they are still wild, they will panic and fight and pull back until their head and chin is sore. They only thing you have taught them is that people suck and so does having a halter on and being tied up really sucks.