check engine light and ABS lights are on

my car check engine light is on it does not blink it's solid, and so is the ABS. now everytime i put my car on drive it makes this weird push and sound i'm not sure why. sometimes when i'm driving on the highway and i'm not pressing neither the gas or the brake because of the traffic the car feels like it kind of changes gears. also the car makes a sound as if my door is opened when it isn't. i want to take it to the mechanic but i work so much i want to figure out what's wrong with it on my own.