I did try that first. SKSE site says:
But when I try and launch skse64_loader it saysCurrent SE build 2.0.20 (runtime 1.5.97): 7z archive
This is a preliminary build of SKSE64 with support for Skyrim SE 1.6.318, aka the Anniversary Edition.
But it is definitely v. 1.6.318 (AE). I had hundreds of mods years ago but this is a clean install of AE. Not working with AE now though. I've watched the videos etc. not sure why it is not working. Might just have to downgrade.You are using a newer version of Skyrim that this version of SKSE64 supports.
That part is for the link below, not the one you posted and downloaded. Here is the full message (not sure why they don't use dividers to make it easier to see what is what though):
This is a preliminary build of SKSE64 with support for Skyrim SE 1.6.318, aka the Anniversary Edition. The plugin manager has been updated with a new versioning system to handle post-AE plugins. If you are a plugin developer, please read PluginAPI.h for the breaking change regarding how plugins report their versions and compatibility with different runtimes.
If you have an existing mod setup on pre-AE that you would like to keep working, this is not a sign that you should upgrade and start using this version of SKSE. However, if you have already upgraded to AE and are feeling adventurous, then try this out.
Preliminary AE build 2.1.2 (runtime 1.6.318): 7z archive
So the link you clicked on is for the SSE edition yes, but the wording below is for the next link, which is for the AE version.
But yeah, their website has much to wish for in regard to the layout, but at least it is there.