"Presente" of regular verbs ending in -are (1st Conjugation)

Which of these verbs belong to the first conjugation?

Which are the endings of the "Presente" of a regular verb?

Which is the right spelling of the 1st person plural "Presente" of "mancare" and "litigare"?

Which is the right spelling of the 2nd person singular "Presente" of "baciare", "mangiare", and "spiare"?

Verbs like "bagnare", "sognare", "regnare" drop the -i- of the first person plural ending (-iamo) of "Presente". Is this true or false?