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.
I'm glad you succeeded at installing something lighter to replace Windows.
Have you search for buying more SODIMM RAM? Buying a 4 gig kit will allow for more room for things to run, and a 8 gig kit would allow the processor to run at full speed, assuming the graphics is also using up dedicated RAM space.
I've used Fedora Plasma and it never came close to using 8GB when using multiple problems, it can go a little over 4GB used. Even though it's a Celeron, the 8GB would allow everything to run freely at full capacity and use more of the processor instead of the processor wsiting on RAM and potentially swaping to the drive.
You can also look at GhostBSD if you want a default GUI desktop but want to try what FreeBSD can do.
I have ordered a 500gb SSD and 8gb of ram (gddr3) All in a a pretty cheap upgrade.
The SSD will make for a very big difference in loading and operation speed, plus filling out the RAM, everything is going to run so much nicer. If the socket can recognize all 8GB, it will be a nicer experience.
I would suggest you have a look sometime at Devuan for consistant stability, light on system resources, and if you using the testing branch you'll never have to install new releases, you only have to do an update.