First thing to do is to check all the fuses and relays.
Checking all the fuses .. is easier than initially thought
Taking a meter or a test light touch on the two test points of the fuse
If there is power to both sides then the fuse is good
If no power at all then the key may need to be turned on
Or you can pull the fuse and test with ohm meter or just a good visual
After that, you can take a look at some of the basics
Check the spark at the spark plugs
Check the fuel injectors
If you don't know how then checking videos on youtube.com can be a great help
Also, plenty of "crank, no start" videos to help you