If he's biting YOU, my solution has been to hold their mouth closed when they do it, and say "No bite"
Say it firmly, but do not yell. We have a 1 year old dog we got recently who had a biting problem, and it solved it rather quickly.
As for potty training, I would say definitely stick with the leash, dogs need to be leash trained, it's very important, even if you have an electric fence. Try taking the little guy out for walks, he won't understand what you're trying to do, but getting him used to the leash is important.
To potty train our dog (She was 1 year old, not potty trained. Got her from a bad home. Never wore a collar or leash in her life)
We took her outside, and waited out there UNTIL she went potty. We would stand out there for 45 minutes if we had to. When she finally did we praised her. Made sure she understood the word "Potty" Or whatever word you want your little guy to know, make it a command, like SIT, LAY DOWN, and more importantly PEE lol.
When our little girl is sniffing or playing, we make sure to pull the leash a little, not hard, just enough so that she feels it, and knows "Oh, gotta keep focus gotta pee"
Good luck to you! Don't lose your patience either, they can sense when you do!