First of all, there's no such thing as "a stable setup that works forever" in linux as a desktop os. Everything changes so rapidly that things become obsolete very fast. Let me use the example a friend of mine gave me some years ago: let's say i give you 2 disks, one of windows 8.1 and one of debian 7. Both of them were released in 2013. Which one would you keep and which one would you throw away?". I think the answer is more than obvious here.
The very nature of linux as a desktop os forces you to move to something newer, because new apps can not be built with old libs, new initsystems can not boot old kernels etc.
I still remember the argument I had with a user here on opera forums, when a new version of opera could not be installed on his 14.04 because it needed a newer version of some dbus lib. In his mind, kde4 and everything else 14.04 had was perfect and everything that plasma and the fresh ubuntu version of that that time had was bloat. In my mind, he was just overreacting, because I knew that flaw of linux as a desktop os. And I even got a downvote for that!
Here is the thread if you want to have a look
https://forums.opera.com/topic/24994/can-t-install-opera-51-on-ubuntu-14-04-lts
As far as your hardware is concerned. According to intel's page here, your cpu may not be an atom, but it is not 64bit capable (32bit instruction set under advanced technologies)
https://ark.intel.com/content/www/us/en/ark/products/27150/intel-celeron-m-processor-430-1m-cache-1-73-ghz-533-mhz-fsb.html
This limits your choices for a distro way too much, because some distros have dropped their 32bit versions completely in the last few years (arch, sabayon, elementary etc) and others have put them in lower priority, e.g. ubuntu has stopped releasing the iso for the 32bit desktop version since 17.10!
On top of that, that low demand on 32bit linux distros is reflected on the availability of closed source apps. Why would opera (opera browser), google (chrome), microsoft (skype, vs code etc) waste resources on something whose popularity is decreasing every year?
To sum up, if you do want to keep opera and have it work on all sites, get some new hardware. Even todays intel atom cpus are 64bit!
If you do not care about opera, find a distro that has 32bit support and is a rolling one, so that you won't have to reinstall it every few years.
