#1
I have a bass, a bass amp and a acoustic guitar. Im in a music school and ive done some small gigs (borrowing some of my teacher's material like amps, mics, a drum kit...) and i would like to have a mic on my house so I could practice my singin, pratice playin a instrument and singin at the same time...

But if I buy a mic I have to plug it in... What would be the best choice? A small amp? A speaker? Could I buy an amp or something with 2 inputs and connect my acoustic guitar and mic at the same time? (Sorry if these are noob questions)

Any recommendations or advices pit? Im kinda in the dark here
#2
A PA is what you want for amplifying vocals and stuff. You only need one powered speaker if you'd be using one input, but for plugging multiple stuff in, you'd want a mixer and at least one powered speaker.