Why is my Wifi Internet Connection Weak, Poor, Slow on my MacBook?

I have a Macbook pro mid 2014 and it seems like my wifi connection is super slow and sometimes doesn't work.

I called the cable company to check and they said nothing is wrong and ran some tests and mentioned it may be something with my own hardware. I have tried to see if the speed is quicker with wifi at coffee shops and at another home. The same issues persist.

Is there something I can replace or need to buy to replace to see if that solves the issue? Like an airport or something?