I'm thinking about getting a bicycle that I can take up and down my street to various shops, restaurants, etc. One-way, the route extend just under 3 miles. The elevation drops by about 100 feet for the first 2 miles, then rises 50 feet for the final mile. (I'll be traveling it both ways, of course.) What rates/grades/inclines do these numbers indicate? Would they be considered challenging for a (non-athletic) beginning rider? Would I do well to invest in a 3-speed or better, or is a single-speed likely to do the trick?