So far my project looks like this(see attachment)
It's not too bad, but not too good either. I want to change this whole setup with a 16x4 display, where i can display solar v, windmill v, batteries v, the amount of amps being pushed into batteries, and amount of amps being drawn from batteries, maybe som watts readings if i get enough space left on the lcd. Now the question is, is there a way to measure those 75mv for each ammeter from the shunt, and the 0-30v ?
The 0-30V is easy. Just use a voltage divider to reduce that to 0-1.1V or whatever the internal voltage reference of your Arduino is. For example 33K & 1K would reduce 30V down to 0.88V.
For the 75mV, you could use op-amps with a gain of around 10 (e.g. LM358 used as non-inverting amplifier with a 10K feedback resistor and 1K gain resistor). Or you could use an external adc module with adjustable gain settings such as ads1115.