Volume pedals come in at all sorts of prices. You can play without one while you choose, That's actually a good discipline for practice because it stops you from "hiding" mistakes by backing the volume right off until you're sure it's the correct note! Serious players will get the best they can afford and it's not difficult to spend £200-300. The most expensive types are electronic and offer many features, less expensive are the "pot" pedals. Pot is short for "potentiometer", so you can't smoke it! In effect it's a standard volume control like in a radio and the pedal links to it in some way to turn the knob as you move your foot. Electronic pedals can be set so as not to affect your sound in any way. Pot pedals have a reputation of doing that.
I've had various sorts, Ernie Ball and Goodrich (pot) and Hilton (electronic) among others, but have regularly come back to my ancient Roland standard (pot) volume pedal made in the 70s for regular guitar. It comes down to what you're comfortable with; I didn't like the extended set-up time to plug everything in and so opted for the easiest type to use; a pot pedal.
There are several cheap pedals out there and will be OK for starters if budget is an issue. Look out for where the jack sockets are, I have to use an angled plug on the output side of the Roland otherwise it fouls pedal 8 (twin neck). Jacks on the toe end of a pedal would also need angled plugs because of the pedal bar; ones on the side are easier to deal with.



