You can reach Bukavu from Rwanda via the borders of Cangungu, from Burundi via the border of Uvira, and from Goma via Lake Kivu or by Road. Due to unresolved wars that continue to this day, as well as the massive crossing of goods over the Rwanda/DRC border, the border crossings can take a great deal of time, as well bribes. Do not approach expecting to be able to buy a visa at the border. Have it beforehand and also be prepared to wait and still possible bribe.
Bukavu is mainly a dollar economy, so plan to use Congolese francs only for small purchases. For shopping, check out the SuperMarket Asante, between the Mayor building and SONAs, in front of the Bukavu Cathedral.
For lunch and dinner, try the Cafe and Restaurant Asante at Supermarket Asante, located between the Mayor Building and SONAS.