That's just geese being geese and figuring out dominance. My girls do it to each other too. Also, depending on the climate, you will probably not get any eggs until next spring, as that is when the traditional breeding season for geese is (February - May). The best way to tell sex is voice sexing. Males make a screechy noise, and females don't really. Also, male Africans will get bigger knobs than females. This may not be noticeable for a while, though. Do not give up hope on them yet - I find it much more reliable to sex by voices and knobs than by behavior.
If you do end up having two boys, they should get along fine as long as no females are introduced, and they were raised together. If you want though, you could get them a pair or two of girls once you have confirmed sex. Do not do this unless the sex is confirmed though, as oftentimes males will get overwhelmed with several females (my gander only likes having 2 girls), and the excess girls will be ostracized from the flock and beaten up by the gander, especially during breeding season.