To start creating your own beats and vocals, start with music creation software. Certain software, such as Fruity Loops Studio, come preloaded with drums, snares, bass effects and samples of a wide array of musical instruments that can help you make a good beat and record vocals over the beat you created.
To make a beat on FL Studio, open the software, click the Packs tab on the vertical menu on the left side of the screen, and choose from different audio samples to build your beat. Click on the samples to hear what they sound like before you select them. Once you have chosen which ones you like, assign each of your choices to a sample slot in the step sequencer, then draw your beat by highlighting the boxes where you want each sample to play in the sequence. Once your beat is done, go to the program's Playlist section, select the paintbrush tool, and paint as many bars of the sample patter as you want to hear.
To record your vocals over the beat, plug a microphone into the sound card, open the FL Mixer and select an empty channel. Specify a name for the vocals you plan to record by clicking the Save Disk icon at the bottom of the mixer channel. Name the track on the file saving dialogue window that pops up, and click Save. Begin recording your vocals by clicking the Record button.