Foot washing is a VERY humbling experience, and it does make me a little nervous every time. I always choose someone I know really well in my church....but in reality, we should pick someone that we have wronged or that we have had bad feelings for.
My church usually separates the women and the men, and it's usually my husband's feet that I should be washing. Once a year they do group together as a whole and I snag my husband right away.
I've never had any bad feelings against anyone in my church, but within family you usually find someone you have wronged in some way or have had bad feelings for at some point.
Are you close to anyone in your church? If so, you could start with someone you're really comfortable with (it's still humbling no matter who you pick) and then reach out to someone else later.
I'm planning on being a nurse so I have to get used to touching people I don't know, but I do know that it can be uncomfortable.
It's an exercise in humility, and to me, that really is important for all of us. It was Christ's example, and I'm very disheartened that most other churches do not do it.
I never partook in communion outside of the Adventist church, and I can remember my dad telling me "you are too young", or "you have to be ABSOLUTELY sure" and he scared me a little with all of that (we were Baptist then). And of course the big threat in that church is hellfire and damnation so that's apparently the consequence of not being ABSOLUTELY sure there.
I just recommend humbling yourself in prayer over it and asking the Lord who you may have wronged, and He will give you strength to approach that person and ask "may I wash your feet?"
I'm 38-years-old and I cry like a small child every single time I take communion. It's very hard for me to accept that Jesus died for MY sins, and I cannot ever be grateful enough, in my opinion, for that sacrifice....and horribly ashamed at the same time.
It's a great experience, and one you won't forget. Every time it feels like the first time.
I hope that helped.