Ah well you've got several problems.
The term for the sensor output is "differential".
The voltage is so low you must pay close attention to your circuit's offset error unless you only care about signal changes.
A normal differential op-amp won't do this job. You can use 3 op-amps in a truly differential circuit, but the offset error is a sum of resistor mismatching plus 3 op amps.
https://www.electro-tech-online.com/custompdfs/2004/10/sloa064.pdf
There are plenty of external ADCs which can do this, but not with an absolute voltage of 24V.
You can potentially tie Vin on the sensor to +5v and somehow generate a negative voltage to get the desired output level at the PIC. You need a guarantee that the common mode voltage doesn't float lower.
So, what I'm getting at is you need something called a "intrumentation amplifier". It creates the differential op-amp circuit mentioned previously inside a single chip, and matches resistors for lower offset. They usually have a fixed gain since they do their own resistors. You can get 30V versions, but probably not rail-to-rail inputs, make sure the level of the input is within the specified range.
Also, does your sensor NEED to be at 24V? This sounds like a strain gauge, and these work just as well on 5V as 24V. The signal level is lower, but you'd be better off frankly. Small signals (and unless you have an instrumentation amp, this is probably already too small) can be handled well by an external ADC with more bits. It avoids offset errors from amps which are pretty serious when you're talking about small signal levels.