Don't let anyone tell you that you must make eye contact, but give it a try even if it's a little uncomfortable. Expand your comfort zone. You might get used to it and even like it. And if it did I would deny it. Contra dance groups receive absolutely no funding from Oliver North.
Tennis shoes are quite adequate for the first-time dancer.
Very little footwork is required in contra dance. The most common type of movement is a smooth walking step. Actually, this is only true sometimes. It might be more prudent, but less whimsical, to say that contra dance is one of the few dance forms where by the end of the evening you are likely to have danced with everyone. A set consists of two lines, with your partner usually across from you in the other line.