i totally understand you i used to train a lot in a park two, on a sort of children bar station. However nobody complain and people always acted positive when they saw me work out. For me not working out is weird :)
15 pull ups in one rep is nice. 6 is not bad man. 2 weeks of work out and you be at 10-15 before you know it. I skipped the pull ups for now.. But im working on dips as much as possible in one row. I will let you know if i will share that.
Good luck there.