If you cannot pull the shift lever towards you with the ignition on and your foot on the brakes, the problem is with the interlock. A bad brake light switch, blown fuse, or other broken circuit can cause the brake-shift interlock to not release the lever. That's the most likely culprit.
The quickest way around it in a bind is to unlock the steering column by turning the key to the UNLOCK position, but NOT to the RUN position. If the dash lights up or the radio comes on, you turned it too far. Then, depress the brakes, and shift to NEUTRAL, then start the engine. You'll have to repeat the sequence every time you want to start it until you solve the problem, but it can be done.
As mentioned, it's likely either a blown fuse for the brake on-off switch, a bad brake on-off switch, or a wiring issue.