Hi
This is the list 9f what you need for your Hw:
1 or 2 HC SR04 Ultrasonic sensors
2 1k resistors and 1 3.3v zener
1 relay module rated to your pump power
Using nodeMcu have the advantage of having all USB interface IC onboard, this way you can just connect to your PC for firmware upload.
To power the unit any simple USB power converter will go.
For connection of the HC SR04 you can follow the schematic of the wiki
https://github.com/pbecchi/SensorServer/wiki/SENSOR-SERVER-Wiki.
You can route the sensor signal to any Esp Gpio,. The second sensor is for the second unit if you want to measure also tank 2 !
The second unit should be connected to a relay board: this device should be rated to your pump need and be capable to be driven by a 3.3v signal!
Again any GPio can be used.
The connections are so few and simple that you can do it with any breadboard board!
Software
One you get one NodeMcu try to compile and upload the Sensor server code, you need to have Arduino 1.6.8 Ice installed in your PC with Esp8266 Arduino Code libraries. You have to download also the driver libraries for the various devices ( I will add a list to the Sensor server Readme)!
If you are successfully then you will have to just modify the config.txt file to define how sensors are connected to the unit and to add a couple of “rules” that will define how to control your relay.
When you are ready I will tell you how to do it !