welcome,
it's not possible to tell you which card to buy because there are many good ones with different features.
to help you understand what you need from a sound card (and not pay a small fortune for something you don't need),
- MIDI is a must for electronic music (for hooking up a keyboard/controlers)
- a pre-amp for microphone/s and/or instruments if you plan on recording them (some cards offer an instrument input for directly recording guitars etc. in addition to any line and mic inputs)
- good sounding d/a converters (read reviews about that and listen to the different cards)
- simplicity & reliability are important
- check the card's system requirments against your computer

and use the forum's search engine (alot)
success