re: question about connecting to the internet directly

Don't touch the modem.

You need an additional ethernet cord to plug into your computer/back of the router. This will give you a wired internet connection.

If you do not have another ethernet cord you cannot have a wired connection, unless you disconnect the cord from the back of the router and plug into your computer. This will knock out your wifi though.

tbh it is probably best you just deal with the slow wifi.