Now this is going to be hard but you're going to have to stop watching porn 😄
Looks like everyones ones covered everything I'd say and great rid of programs you don't need and stop the ones you do from starting up straight away.
A good test is to start your laptop, then get up task manager and see what your RAM and CPU is running at. If half your RAM is getting gobbled up by it just sitting there then the chances are it's going to slow down when you run extra shiz.
In terms of buying computing shiz, always look buy good parts that aren't going to be obsolete in a years time. Someone at work was looking to buy a gaming laptop, the one they had chosen was good but I suggested to wait another month and save up more so they could by the version up. A lot of issues is people say they want to use it for gaming but then end up putting all sorts of software and going on to all sorts of funky sites. Phil's done it right, he's kept his a gaming computer. This also helps him to narrow things down if stuff starts going wrong.
Sorry saw this post the other day but was just finishing up lunch and was going back to work.....then forget 🙈