Can I use the fridge still without plumbing in water,model Electrolux ERES31800W
In general, plumbing water to a fridge is only required in order to use the ice maker and water dispensing features. You can use it as a fridge with just electricity connected.

Typically, there is an easy way to shut off the ice maker. If you don't have water connected you should do that in order to reduce possible wear on electric valves and other parts. You may also be able to disconnect and temporarily remove the ice maker so you can use the space it would take for other purposes.