what's the subject?

[karen mae]

hello teachers,
It's getting late. We have to go home. Come on. Let's go
In 'let's go,' what is the subject? What sentence pattern does it follow?
My friend told me it is as imperative sentence, giving an order or command but the sentence also involves the speaker. Does that mean im giving an order to myself as well?
Another friend of mine said that the subject is 'let' which i believe is a verb.
Is it possible for a verb to function as a subject?
What is a nominal subject?
thank you and best regards.

[MrPedantic]

Hello Karen

"Let's" serves as an 1st person plural imperative, as your friend says.

In an imperative sentence, the subject is implicit:

1. Go home at once!

– implicit subject "you": "(You) go home at once!"

So in this sentence,

2. Let's go home!

– the implicit subject is again "you":

3. (You) let us go home!

MrP