Network unstable

[hehi]

I keep seeing unknown devices on my network and I can’t go to many websites. Redirected to not secure sites . I have a tm3200 and another router that I don’t know how to configure. I am worried about network and if it is secure , help

[NFtoBC]

Why do you have two routers? 
If you need additional Ethernet connections, a switch is a better choice.

What happens that you get redirected? Are you not being sent to the sites you choose?

Note, due to changes in internet protocols many secure sites are being reported as not secure in browser URL bars.