gear not engaging

Hi all, I'm starting to diagnose and attempt to fix a few problems on my 2004 Forester X Auto with the intention of selling it (I recently purchased a 2006 XT :cool:). One of these problems is the transmission not being able to upshift into 3rd gear once the car has reached operating...

2004 Subaru Forester EJ20 Manual transmission I just took out my car for a drive , gears didn’t engage after kms later after few minutes the gear started functioning with some noise ... What will be this issue ? How should I sort it out ?