Hello, Please help me with these.

Go on F a c e b o o k or I n s t a g r a m.
Is it ok to use Go on?
What other verbs can collocate well.?

Say pray
Say prayer
Which on is correct?

Thanks,,,,,

Question

Hello, Please help me with these.

Go on F a c e b o o k or I n s t a g r a m. 
Is it ok to use Go on?
What other verbs can collocate well.?

Say pray 
Say prayer 
Which on is correct?

Thanks,,,,,

Answer

"Go on" or "get on" works here. You need an article or additional word in the second one: "Say a prayer."

Answer

Go on is fine
Get on also works

You need an extra word in the second one:
Say a prayer
Say your prayer

Or you can use pray:
Let us pray
Time to pray

Prayer is a noun, pray is a verb