Now that we've settled which use you're referring to, we can say what these expressions can mean. So usually in informal speech and among certain demographics and regions "to be like" can mean "to say", "to respond", "to think", "to feel", and probably many other things.
"to be like" when used in this way I'm pretty sure is always followed by direct speech, even though nothing may have been said.
- He told me something, and I said there was no way that was true.
- He told me something, and I'm like "No way that's true!"
- He told me something, and I was like "No way that's true!"
Notice when you use this you use direct speech as opposed to indirect speech (reported speech). The difference being:
- Direct speech:
He said "I'm not going to the party."
- Indirect speech:
He said that he wasn't going to the party.
Often it means something like "I/he/she/etc said", but that's not the only thing it can be. Take the following example:
- I forgot to bring my umbrella for the first time and it started pouring, and I was like "You've got to be kidding me!"
Here "You've got to be kidding me" isn't spoken, but most likely a thought or feeling, although it's possible the person verbalized it, maybe screaming out in rage. It's not exactly possible to know all the time.
He told me something, and I was like dude really?
This can mean many things. Something is told to the recipient, and the recipient either responded with the exact words "Dude, really?", or something along the lines of "are you really serious?". In addition it's not necessary that the recipient actually says anything. "... and I was like dude really?" can just be an expression of a thought the person was having. More often than not it usually means it's a verbal response, but again, we don't know exactly, without the context, whether the actual words "dude really?" were uttered.
I was going along the street, and suddenly something happened, and I was like WTF!
In this example it's much more likely that nothing is actually verbalized, and further, that we can't tell whether a person was thinking "WTF!" or "What's going on here?" or "What the hell is happening?" or "I'm confused" (It's kind of hard to know what words are going through a person's mind).
So again, the direct speech that's mentioned after "to be like" may be the actual words spoken, or not, or maybe no words were spoken at all.
- I offered him $20 for the item and he was like "No way!".
We don't exactly know whether he said "No way!" or something else such as "I'm sorry, I'll have to decline that offer" or something similar. In addition it's possible after having made the offer the person didn't say anything, but just turned their back and walked away. In this case the "No way!" is the storyteller's way of saying that the person refused the offer. It's not exactly possible to know what was spoken, if anything, in many cases.
This usage is very normal, but informal.
I know this might sound complicated, and I'm sure there are extra nuances and things I got wrong, but that's the gist.