You will not be able to connect to a TCL Roku, as they are analog and the Roku is digital from start to end, but depending on the number of connectors, you can connect directly to the SCART display connector your TV should have. That is basically the old age HDMI socket.
Check the yellow lead, if there is only one solid metal piece in the middle like an RCA phono connector, then it should work with 'Composite to scart' connectors... or 'Direct RF/DIN to HDMI' if it's protruding sharply or cut off at the top and hollowed out but like RCA otherwise.
RF/DIN may have a dial on the box that is to tune in VHS and PS1 consoles that would come with adapters that directly connected to the TV's radio antenna socket. You'll know what I mean if it is, and other than that it will still look like a phono connector.
Finally if instead of a solid piece in the middle, it's got lots of little pins in it like old PS2 keyboard connectors, it's S-Video and you will need an S-Video to HDMI adapter. You are lucky because, being digital already, the connectors will not suffer the same wear that the other adapters here will. Analog/Digital conversion is a number one spot for dodgy cables.
You didn't mention the exact model, but this TCL Roku tv has an "AV In" jack:
The tv should come with an adapter that has a 1/8" TRRS connector on one end (it's the one with the long tip) and rca females on the other (the yellow, white and red ones). Plug the 1/8" TRRS into the tv AV In and plug your VCR cables into the correct color female jacks on the adapter. It looks like this:
The adapter above will work if your TV has an AV input. It sounds like your VCR is mono since it only has one audio output.
If you want sound to come out of both TV speakers you will need a audio Y splitter with 2 male and 1 female plugs as well as the adapter.
Some TVs do have RCA AV inputs. Some have a shared component - composite video input. Check the TV manual. You would still benefit by using the splitter.