The placement on the screen of “recorded in” and “recorded at” is just cosmetic. I agree it looks odd though. As @highstrung points out, on other pages they are together.
For those tracks that you do know about you can update the recording date on the right hand side, and the recording location on the left hand side of the Edit Relationships page.
For those that you are not sure of, just leave those without extra details. There is a general rule around MB of “If in doubt, leave it out”
Just by doing that may be enough of a prompt for someone else to come along and fill in more details from a different source.
Importantly - any edits you make like that it is good etiquette to note your sources.
Like many areas of MusicBrainz, it can be all a bit confusing\intimidating the first time you try something. But dive in and give it a go, we’ll have a look at the edits and make sure it all looks good.