The school PTA / building relationships

Hi everyone,

First time posting. I have recently begun to self identify as Autistic as I am still awaiting diagnosis but as I learn more about Autism I've become fairly certain. Please excuse anything I say that is wrong - I'm early in my journey of learning about myself and about ASD. 

I was convinced to run my kids school PTA last year which I took on without really thinking through the people side too much. On a regular basis I seem to manage to upset people and just can't understand why. For example yesterday the school asked the PTA to help put a large donation away, I went to help and as a result, one of the key team members is so angry with me that she has quit! 

When I ask my neuro-typical wife / anyone else, they can quickly and easily identify what I've done wrong. I find the idea that I have upset someone when just trying to help raise money for a charity very hard and it knocks me for a few days each time.

The advice that everyone gives me is that I need to "build relationships". I agree 100% that this would help alot but... Well what does that look like?! I'm told to take them to the pub and get to know them... not sure me sat in a corner feeling awkward is going to build many relationships, particularly as most of the rest of the team are a friendship group!! 

Any advice / thoughts would be welcome. Clearly quitting is currently in mind but it's unlikely someone else would take the role which means we have to close.