Simple Measure Weight and Temperature for Kegerator project

Hi Noob here, not to technology or electronics but to Arduino.

What I want to do sounds very simple to me, I am OK with attaching the electronics and all that, its just the programming side of things that will trip me up.
I do however learn pretty quick once I see the code and follow it to understand what its doing.

These are the requirements for my project
Have an LCD screen (plain and cheap) that displays how much is left in my keg, fridge temp, and possibly the CO2 Pressure.

I was thinking of using a weight sensor, having a value for the empty keg stored, and then placing the full keg in the fridge onto the sensor pressing a button to set the new weight and then it works its calc from that?
I know you can use flow sensors but the ones I have seen are to expensive.
Fridge temp was going to use a simple DS18S20

I realize that there is Keg bot, but I really would like to keep this project well under $50 if possible

If any one could help me, maybe write some simple code and point me in the right direction for the parts that they use for the coding.

Thank you in advance.

Best Regards