So my wife has a 10 year old low end notbook. 500Gb of storage (HDD), 2GB of GDR3 RAM, and an intel Celeron Processor N2806. It originally came with Win 8, then she "upgraded" to win 10 and after that it was pretty much unusable. I am talking CPU and Ram about 80-90% in idle, opening a browser got everything down to a crawl. She mostly used it a storage and brwosing, watching youtube and occasionally to write. So I (also a Linux newbie) finally got the time to install a newbie friendly Os (Fedora) and it's so much better! I am Talking 20%CPU usage and 50%(?) RAM in idle.
Allright, my promised update: My Ram finally arrived and I happily put in the 8gb and... It went all south. Horrible boot time, bad performance the whole 9yards. Bios (thank you HP) didn't even let me change the clockspeed of my ram. Anyways since I wanted to give my Wifes Laptop (her active one) an upgrade anyway I got the 8gb ram in her machine and that one works like a charm (-windows). So I had 4 gb left now (from her machine). Well, I stuck that one in this linux machine and they now play nicely.
So all in all a great success story! Thank you for encouraging me to upgrade it!