In all electronics, custom devices can cost thousands of pounds to get the first one made. However there are lots of LCD screens that are quite easy to use. So you don't design an LCD screen, you use a standard one.
They do need software.
For the pressure, temperature and volume you have to measure each one separately. There are lots of temperature sensors, and quite a lot of pressure sensors that are available. For volume, you need to measure level or float angle or something, and guess the volume based on the shape of that container.
Each sensor will have a different type of output.
I would find a sensor, preferably with a digital output, so that it is easier to connect to a microcontroller. I would test the sensor to make sure that it is actually measuring what it is supposed to, by writing a short programme to read the sensor and turn on an LED if it was above some value that I could easily get it to reach.
For instance, on a temperature sensor, I would aim for 30 dec C or so, so that I could warm it with body heat and the light should come on, and then when it cools to room temperature, the light should go out.
I would then do that sort of check for each sensor.
On the LCD, the first thing to do is to find a general purpose screen that could be used. Search this forum as I think that some mobile phone screens are interfaced with just a couple of wires and they cost nearly nothing.
I would then write a short programme to get the sensor to output a fixed reading, like a name, or that old cliche, "Hello World". Once I had done that, it's quite easy to take the output of the temperature reading program and send that number to the input of the LCD driving programme.
If you can't programme a microcontroller, you'll have to allow some time to work out how to use them first.
Good luck.