Neither of them is needed. "Let's go have breakfast."
Student or Learner
1. "Let's go and have breakfast."
"Let's go to have breakfast."
I think that after "let's go" we do not use "to" before the verb,instead we use "and" but I am not sure. If I am right could you please clarify the rule?
As a BE speaker, I prefer 'Let's go and have breakfast'.
There is no 'rule'; it's a matter of usage.
Ｉ ｔｈｉｎｋ ＂ｌｅｔ＇ｓ ｇｏ ｆｏｒ ｂｒｅａｋｆａｓｔ＂ ｉｓ ｂｅｔｔｅｒ， ｂｕｔ Ｉ＇ ｍ ｎｏｔ ｓｕｒｅ．