My College email account was hacked and several dirty messages went out to my teachers and boss. My Snap Chat was also hacked and messages were sent out to my parents only. How can I find out who did this.
Depending on which email service provider you are using, you may be able to check the IP address from which the dirty email came.
To do this (with gmail), first, view the email that you would like to track. Find the drop down arrow next to the reply button, and select "Show original". Scroll down and you should be able to see almost everything about the email including the sending and receiving IP addresses.
Go here to see a more detailed tutorial including what to look for in the original message (varies for ESP). After you have the IP address that you suspect to be the attacker's, insert it into this free IP Geo-locator.
Note - make sure the IP address that you extracted from the email is not yours or your ESP's.
Firstly, for your college email account you can consult and report it to your school administration. They will investigate your login activity and they can check the email header to figure out the source of those malicious emails. So basically they will do a forensic scan of your account.
Secondly, for your Snapchat Account, you should enable security features of login activity and also the 2 factor authentication by adding your cellphone number or you can use Google authenticator https://support.google.com/accounts/answer/1066447?hl=en
To figure out who accessed your account, the Snapchat team should be more than happy to assist or if you want to go further with this, 3rd party services can do the investigation for you as they know the legal procedures need to be followed.
To stay alert, I would recommend signing up to services like https://haveibeenpwned.com may be your email was leaked on a certain site and they got access to your credentials.