Yo shy! Welcome to the board! First- that's not a piano. A piano is a thing which is made out of wood, with strings. It doesn't plug into anything. Your keyboard apparently has a USB output, and it may or may not have a round socket labeled "midi out". Let us know that, because whether your keyboard is midi enabled will affect your options on how to record it. In any event, it will not require a microphone to record it- no wood, no strings, no real sound=no mic. As far as the vocal mic goes, basic beginner options are a dynamic mic or a condenser. They are different, and some will prefer one or the other to start. For an entry-level dynamic, standards include
Shure SM58 and Sennheiser e835. Behringer builds a pretty good one dirt cheap ($20 new)- XM8500. For a cheap condenser, I like the Marshall Electronics MXL V67G mentioned above- about $100, or Studio Projects B1- about $130. I'd buy the XM8500 and the MXL V67G. That would give you 2 flavors for your palette for about $120. One or the other may work better for you.
Here's the problem- Real mics *don't* plug into a computer. The "mic" input on your soundcard is designed to use a specialized computer mic which essentially, is wicked cheap and sucks. Secondly, your soundcard has a nearly useless preamp that sucks. So- you need a computer interface, which real mics can be plugged into, which provides one or more preamps, phantom power (which is required for condenser mics like the V67G), and an analog to digital convertor, which converts the mic's signal to a digital signal and sends it to the computer, usually by USB, sometimes by firewire. The interface essentially bypasses the cruddy soundcard, and becomes the soundcard for the purposes of recording. It also gives you a headphone output for monitoring, and outputs for some kind of speakers for playback.
If you need to record the keyboard and vocals simultaneously, you can send a line out from the keyboard to the interface. If it doesn't have a dedicated line out, you can use the headphone jack. If you have 2 USB ports available on the computer, depending on your recording software, you *may* (or may not) be able to record the keyboard by one USB and the vocals, using the interface, to the other USB.
If your keyboard has midi out, an interface with midi capability may be a bonus, allowing you to use the keyboard as a midi controller, accessing everything from better piano sounds to drums.
Here is an example of a 2 channel interface with midi. It should be just what the doctor ordered:
M-Audio Fast Track Pro | 8thstreet.com | Call 1-800-878-8882 | Free Shipping on most orders!
Here are the mics I mentioned:
Behringer XM8500A | 8thstreet.com | Call 1-800-878-8882 | Free Shipping on most orders!
[url=https://en.audiofanzine.com/dynamic-microphone/shure/sm58/user_reviews/]Shure SM58-LC | 8thstreet.com | Call 1-800-878-8882 | Free Shipping on most orders![/url]
Sennheiser E835 | 8thstreet.com | Call 1-800-878-8882 | Free Shipping on most orders!
Marshall Electronics MXLV67G | 8thstreet.com | Call 1-800-878-8882 | Free Shipping on most orders!
Studio Projects B1 | 8thstreet.com | Call 1-800-878-8882 | Free Shipping on most orders!
Hope this helps- Richie