No Crank?

I recently bought the vehicle listed above Quattro from a buddy who was trying to get rid of it for $1,500 USD, the previous owner who he bought it from said the serpentine belt went out and he didn’t replace it immediately so the car set causing the battery to die he had the wrong sized battery in so I replaced it with the correct one after realizing it was a bad battery, although having a new starter in it the car won’t crank, the MMI will turn on very briefly before turning back off, I do have access to interior lights, I’m able to turn on the hazards, check the mileage, the seats will go back on both sides, when it comes to the horn it won’t produce any sound, the windows will not roll down and the driver's side doors won’t lock (I’m able to open the trunk and lock the passenger side doors.) And the main issue, the car will not crank, sometimes I can hear a very faint clock but it will just produce no sound most of the time, can anyone please help me out with this I just bought it as a project car, but it’s a pretty nice car so I do want to be able to drive it.