What does it mean when if feels awkward talking to someone?

It can actually mean (sometimes) that you get exactly what they are saying and whit that means about them

”..... I normally say hi to..”
Because you normally say Hi to him he assumes that you wish to continue the discussion to get to know him more?
Maybe he felt awkward starting this conversation?
Confusion is sorted out when you can discuss friendship boundaries etc.
Like for example say” I don’t like to get into relationships too fast so I prefer to be acquaitances/friends first in order to get to know each others shared interests or not?

It means you have little or no self esteem.

It can be that you like the person, and so you are nervous.

It can be because they are in a position of authority and that makes you nervous.

It can be someone who you feel is judgmental and so you are thinking they are going to comment on your grammar or are judging you in some other way.

It was was awkward because you picked up a social cue that told you to stop, and for whatever reason, you didn’t. So in a very small way you were rejecting him.

I think you can have a conversation with someone without any desire to swoop them off of their feet or in your case, wanting to be swept off your feet. I suspect the world will continue to spin if we don’t size up everyone we know of the opposite sex, as a potential love interest. Good grief…!

Social anxiety, or maybe you just found their question on the awkward side.

it means that your normal routine was interrupted and was unexpected and so through you off your feet. I don’t think you will feel this way again