Welcome, Andrea, to the OEM forum.
Much has been written here about the DS18B20 sensor, so you have a lot of reading to do.
First, a very full explanation of the One-wire System -: https://dutta.csc.ncsu.edu/csc453_spring16/wrap/1-Wire-Design%20Guide%20v1.0.pdf
Wiring DS18B20 sensors: DS18B20 reliability considerations
Much about clone sensors & multi-drop: Ds18b20 and emonTX3CM firmware - post 78 in particular.
Temperature sensors don’t work: http://openenergymonitor.org/emon/buildingblocks/DS18B20-temperature-sensing
There are two articles in the ‘Learn’ section here: Learn→Electricity Monitoring→Temperature
Maxim App Note re wiring: Guidelines for Reliable Long Line 1-Wire | Maxim Integrated
1-Wire DS18B20 direct to RPi: Enable 1-Wire Interface on the Raspberry Pi - Raspberry Pi Spy
And we have a sketch for an emonTx (or Arduino) to read the sensor serial numbers - knowing those can be very useful.
I think your best approach will be to read as much of that as you can absorb, then come back with questions.
“The Shop” sensors come with a fixed length of cable - if you have more than a few sensors and they are all some distance away, you will be much better arranging your wiring as a proper “bus” or daisy-chain, rather than bringing all cables back separately to a central point.
Don’t worry about that, we all were, once. If you’re prepared to ask questions and learn, and follow up our suggestions, most people here will stay with you and provide all the support that’s practical. Except for the 2 owners (Glyn & Trystan) and Gwil, we’re all volunteers. The one thing we don’t do is 1 to 1 phone calls (or whatever) - it’s all on the forum.