There's a lot to be said for calling in a licensed electrician. Especially when dealing with older houses that may have had "help" over the years. And by "help" I don't mean code-compliant wiring. Lots things get installed in ways that don't follow code or don't even work properly. A decent electrician is going to have some experience with this sort of thing and figure it out, quickly and solve it safely.
Do you know for certain how many circuits are feeding this box? Is it just one? As in, you power off the fuses/breakers and determine that just ONE is feeding the box. That's important, you DO NOT want to mix circuits, which is a mistaken often made.
Then find the hot that feeds the box. Use that to power each switch. Lots of times someone that doesn't know what they're doing will do something like push the black into one switch and then use the screw terminal on that switch to power others. It's better to attach pigtails to the hot and feed each switch individually. The white neutral wires can likewise be pigtailed to any switch that needs it. But for regular non-automated switches it's common to take the neutral from the breaker and tie it to each load in a single large wire nut. It's just the hot you need to contend with for non-automated switching (this is commonly black wire, but could be anything).
Start by creating a drawing of the wiring for what's being controlled through that box (ALL OF IF).
I'm guessing you're going to discover some shenanigans with how someone else did that wiring in the past. SOLVE THAT. Don't just bang your head against what's unknown. Figure it out, or call in an actual electrician.