I’m not sure whether dashcams without GPS exist. Speed and location are essential part of the recording, should it ever need to be used legally. What is your problem with it recording your speed? I seriously doubt whether it can ever be admissible as evidence against yourself. In fact, it takes a court order to release the footage for third-party viewing against your will.
I’ve got a simple Mio dashcam which cost less than 100 Euro. The setup was: stick it to the windscreen, plug it in and switch on. I hid the cable behind the windscreen surround, it took me all of ten minutes. It has been functioning perfectly for four years now. And yes, it has GPS and warns for fixed speed cameras. Reminds me; I should update it one of these days.