Cant use internet on mac

Normally there should be no proxy set, if this is a home mac.

If it is a managed mac (like an office or school lab) you may need to check with your IT guy.

If it is a home mac, there is a chance that you may have gotten some adware or other potentially unwanted program that has changed the settings improperly.

I suggest you turn off these proxies, and also run the diagnostic tool Etrecheck so we can evaluate possible infection or other issues.

Are you trying to reach a website, in Safari, or another browser? What exactly happens?

How are you connected? Wifi? Ethernet?

Open System Preferences->Network.

What is the color of the dot next to your connection: green, yellow or red?

What are the settings? DHCP?

Does it show a "self-assigned IP" of the form 169.*.*.*?

If it is green but you can't connect, click Advanced, then in turn click DNS and then Proxies, and tell us what you see in each (or better yet, post a screenshot).

Don't fall for that!!!!!!