connect my laptop to the router

I am trying to connect my laptop to the router with cables provided by the cable company. The cable from modem to router is a Cat5e. It fits into the 4 LAN ports on the router, but it's too big for the LAN port in the laptop.

will these fit in the laptop?

Pearstone 14' Cat5e Snagless Patch Cable (Blue) CAT5-14BL B&H

There is generally only one size of ethernet cable to plug into computers, RJ45. On some laptops, the opening enlarges as the cable goes in. What laptop are you trying to use? Are you sure you are trying to plug into the ethernet port not phone-RJ11, and the laptop has ethernet?

Alright, it fit finally. Just had to lower the notch and push the cable in harder.
I could hear Cochran saying: "if it dont fit, try harder to make it fit".

I will now attempt to use the Internet using Ethernet cables instead of Wi-Fi and see if I get better results than 25mbps.
Any further instructions as to how to set it and forget it?