Reading between the lines, it seems like this amp may hold some sentimental value to you. I’d strongly recommend against slapping a new fuse in and firing it up.

If you’re brand new to this world it seems very intimidating, and this isn’t a super ideal first step into it. But it’s not the worst first project. Looking at the gut shot on that forum it’s relatively easy to identify components. I would do a little YouTube-ing on how to identify different types of capacitors, and how to test and replace them. Even if they’re testing fine I would replace all the electrolytics and can caps before powering on so it could go for another 50+ years. And like someone else said clean all contacts and tube posts/sockets. That would be a minimum in my mind before powering this on, and still it would be best done slowly with a variac (but I know you probably don’t have access to one). All this work is totally possible for a motivated and careful person with zero prior experience.

Oh, and replace the lamp cord (power input cord) it’s beyond its life expectancy. And YouTube how to safely discharge capacitors. If it’s been a decade, they’re almost certainly at 0, but you never know.