If you search “N64” using the search panel, you’ll find a lot of useful info.
Update your setup script, and you will be able to install the mupen64plus-testing emulators. I found that the mupen64plus- testing with the gles plug in runs the best overall, while the rice plugin runs Zelda better. MANY GAMES WILL NOT RUN PROPERLY NO MATTER WHAT YOU DO. That said, the Pi2 will do better than the B+ – you should set the overclock to “Pi2”. My memory setting is 256MB.