I've read that older people usually don't need to shower every day ... every other day is fine, unless you have been doing something that makes you sweat. But you should change your underwear daily.
Anyway, your bathing habits have nothing to do with being a nice guy.
If you cannot walk well, assuming you are a man, do feel that it makes you look weak, or old, or something else? My sister worked for Social Security long enough to retire, and she saw a lot of men who did not use walking aids, for instance, because they didn't need them -- even though they could barely walk. Their wives, who were usually with them, were very frustrated about that.
As far as being "scared to death", you'd have ask yourself what you are afraid of. Ice-cream is not a gateway drug to marriage or to sex or to anything else, really. Maybe you are shy, or self-conscious. If so, maybe you could have the courage to try something new, knowing that it won't kill you. It's good to try new things, get out of your comfort zone a little bit.
This is not necessarily a "date", anyhow. Lots of women like having nice guys as friends. Or they at least want to start out as friends.
And you should take normal safety precautions -- meet the woman at a public place. Do not drive off with her in your car, or you in her car. You don't know her. It's always good to take your time getting to know people, especially those who like ice-cream.