First off the key to starting rap is you need to have a "flow" like I stated in the beginning. So start off by freestyling and clearing your throat. With freestyling the key is to start off small to build your word association. Remember that from grade school. Word association is *example - DUCK, LUCK, MUCK, SUCK, BUCK..... and so on*. Now Practice freestyling with your friends and improve at this. Also at this time You'll need to find out what your style is, Yukmouth has a Nasty Monsterous voice, Method Man has a grimey cloudy voice, Snoop dogg has a Laid Back style like Richie Rich, Twista has a fast tongue twisting style, Bone thugs n Harmoney all have the Fast yet Harmonizing singin style. Find what youre most comfortable with and it'll be your gimick or whats actually known as your "LYRICAL PRESENCE"
then this brings us to step 3
Freestyling - means rapping without having time to write anything down.
ill use this video from youtube i made for how to freestyle as an example cause i feel it still applies to this guide