shoul have confidence

please clarify this for me.

you should have confidence to do it.

you should know before start doing
people should have moral resoponsibility.


My intention is like ....I want to tell someone about my friend who is not aware of lot of things, then Can I use this sentence.

"he should have learn lot of things.".

these senteces are correct, if not correct me.


Looking forward your valuable information.

Regards,
Madhu