What is it that you're seeking to do with the VCR? Are you simply trying to play old tapes or to actually record programmes with it?
In the 'good old days' of analogue TV, your VCR could record one programme, while you watched another on your TV, because you had two separate analogue tuners in use. The one in your TV set fed a picture to the screen, while the one in the VCR fed a signal to the tape.
We've now moved onto digital TV. You've only got one digital tuner (in your TV) which can only feed a signal to the screen. (It can't feed it to an external device). So your VCR can no longer record programmes. (It's technically possible to feed a signal from a separate Freeview box to it, but things get very complicated when it comes to connecting leads). If you're seeking to record programmes you need to buy a recording device (such as a PVR or DVD recorder) that contains its own digital tuner.
If you're only seeking to play old tapes, then your VCR will still work. If your VCR and TV both have Scart sockets you should simply use a Scart lead.
If your VCR has a Scart socket but the TV only has RCA sockets (which are the red, black and white 'phono' sockets) you need to use a 'Scart-to-phono' cable. If there's an in/out switch at the Scart end, it needs to be set to 'Out'.
If you're seeking to connect the two devices using RCA ('phono') sockets at each end, you should check that the sockets on the VCR are labelled 'Out'. (Quite often the RCA sockets on a VCR are only for accepting an input from an external device, and thus useless to you).
When you're sure that you've got the connection right (and that you're definitely connecting to an 'output' on the VCR and not an 'input') you then need to select the correct source via your TV's menu. If you've plugged a cable into the Scart socket then the source may well be shown as 'Scart', 'Scart 1' or 'Scart 2'. Otherwise you need to try 'Ext', 'Aux', 'AV', 'Input', or something similar. (The actual label varies between models). Remember to actually have a tape playing when you're trying to find the right option, otherwise you won't know when you've found it.
Chris