crashes every time i hit play

Put the summary of the bug you're having here
crashes every time i hit play
What I expected to happen was...:
Describe what you thought should happen here i thought it would start up but it just cashed im new to minecraft pc and i want to know if its normal

What actually happened was...:
Describe what happened here it crashed

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here i log on to minecraft
2. ... i hit play
3. ... it loads and than it crashed