If anything that’s a great learning environment. Offensive security is a lot of reverse engineering, figuring out how stuff works based off (extremely) limited information and understanding how best to attack it.

Moreover, as these are old systems, they’re more likely to be outdated and vulnerable - not that you should try without permission or a clear understanding of what you are doing, particularly on production gear.

At any rate, no company will pay you to learn a completely different job to the one they hired you for. So you’re going to have to spend some of your own time learning about security. Where to start has been repeated ad nauseam online so I won’t attempt it.