Pipe tobacco, kept properly, should never really go seriously dry. In addition, it's all in what you define as "dry" for smoking purposes. If you're new, you might assume tobacco needs to be heavy and practically sopping wet compared to how a cigar or a cigarette feels. This isn't so, though some manufacturers tin their tobacco in a pretty moist state (far moister than should be for a good smoke, if you ask me).
Now, as for keeping properly, for bulk 'bacca, you can use old spaghetti jars if you're really cheap, or you can go to a hardware store and get rubber-seal Mason jars. You can keep tobacco in the tins and cans in which they come (which, incidentally, fit nicely in a sandwich ziploc bag as a secondary barrier to the tin). No, the antique/vintage glass humidors don't usually work too well. Cigar humidors work great for cigars, and not so great for pipe tobacco. Adding apples or bread slices will substantially increase your risk that mold might ruin the whole batch...so, obviously, avoid that old saw.
How about re-hydrating already dry tobacco (for example, tobacco that is autumn-leaves-on-the-lawn dry, or crumbles like corn flakes)? This thread is a good read for some ideas:
https://www.brothersofbriar.com/t17377-mad-about-tobacco-drying-out-9oz-of-squadron-leader
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