Distribute the Internet on 2 subnets?

Question

network hardware

There are two subnets (router ip 192.168.30.1):
192.168.30.x
10.0.0.x
There is a tp-link Archer C20 router.
It is necessary to distribute the Internet to both subnets. I use 2 router, but the speed has dropped by half. I was told about routing, but after experimenting with the D link router (which has these functions), I did not achieve anything.
Please help.

Answer 1

routing functions are in any router, otherwise it would not be a router
coffee grounds suggests that you have a high-speed tariff and an ancient router that is unable to digest such speeds, as a result, cuts the speed