You can browse the old forum in a read-only mode here:

The search function doesn’t work in the old forum but you can use Google instead.
When you search on Google, type this in front of your search term

However, the links that Google saved are now all broken.  What you have to do is copy the link address, then in a new browser tab, paste the address into the URL address bar and type -legacy after the word forum and before you should land on the relevant page.