Sacrifice for your children. They know when you don't and they notice when you do. Kids look for role models, so have it be you. Treat your kids with respect and kindness. Keep your sense of humor.
Nobody is perfect.
Dads should feel free to jump right in and parent. If your child's mother is at all hesitant to let you in, she may become relieved to see an enthusiastic, confident dad ready to share duties. You are already ahead of your dad because you want to make the journey to closeness. Find out as much as you can about your father's birth family. This information will give you essential clues to understanding dad's personality.