I'm a self taught admin and we DO have a domain name. I'm having trouble understanding all the docments on this subject. How do i find out what Things we may have built that will require me to do something?

I'm not a developer, and I need to give a third party access to my sandbox. I just created a sandbox, but I can't login. I tried messing around with the "View Setup and Configuration" permission...but I'm not having any luck. 

Once I figure out how to login, how do I grant access to the third party?

Any help would be much appreciated!

I have a sample data and based on that I want to create a simple heat map that has color representation.How can I do that?

I'm simply looking for a custom link that will do a search on LinkedIn from the Account and Contact tabs.
Account Tab would do a "company" search within LinkedIn.
Contact Tab would do a contact search within LinkedIn