MacBook turns slow

4GB of RAM is a huge struggle these days, and Microsoft Apps are not well optimized for the Mac, in fact Word will easily chew up a gigabyte of your RAM and as a result macOS will start to use your SSD as RAM which is not nearly as fast so at that point performance will take a hit, and things become slow. Something that helped out other people that were in a similar situation was to use Apple Pages, which is Apple's version of Word, which uses a lot less system resources, and you can save Pages documents as a Microsoft Word file.

Download this free app called EtreCheck from the Mac App Store and post the report here and it will help us see what kind of problems there are. https://apps.apple.com/us/app/etrecheck/id1423715984?mt=12

I would see if MalwareBytes can remove the adware from your computer, if not I know many people that have had success with this paid app from the Mac App Store: https://apps.apple.com/us/app/antivirus-zap-virus-scanner/id1212019923?mt=12

First of all - Etrecheck has detected Adware that is using great amounts of processing power. This needs to be found and removed right away.

Also, the reports say System modifications - There are a large number of system modifications running in the background. Definitely not good

Also Steamclean - is another App that modifies System files to the point of impacting and or destroying the Operating System - remove it via Developers Instructions

Consider carefully before downloading anything. Double check if the Developer is Trusted and offers the ability to Install their App. Be careful from where you download Apps & extensions. And very important, only download what is needed not just wanted. The two are totally different in Apps and in life.