Hello and welcome to the forum! As a new user, you could need to read this page before getting an answer:
You will probably need to build a first graph based on what is already available online (the search tool on top-right of this screen can help). It will then be possible to get help here on specific issues.
You will also find good basics on these pages:
http://dynamoprimer.com/en/01_Introduction/1_introduction.html
http://dynamoprimer.com/en/Appendix/A-4_example-files.html
http://dictionary.dynamobim.com/
Good luck! 