You have a hardtail MTB, probably from around the late 2000's.
I notice a threadless stem, and a larger than normal headtube, but it looks straight not tapered.
Point The front brakes are on the rear of the fork tines. That's relatively uncommon, and may help. However, there's no guarantee the fork is original to the frame.
Shimano didn't make bikes, they only ever made groupsets and componments. So those stickers are just that, labels added by some prior owner after removing all the paint work.
It is a triple chainring, which was still common in the 2000's decade but now only exists on low-end modern bikes. Altus as a groupset was a practical cost-effective groupset that was above the bottom entry Tourney, but was also not ranked with Deore or anything "high end"
Its a nice bike, as long as you like it and the bike is a good fit for you, the exact brand and model really don't matter at all.
If you want to add some personalisaion, get someone to do some vinyl-cut letters saying "Mary's Awesome Bike" or whatever you like, and stick them on, then spray a clearcoat on top.
This bike is slightly older than your previous ID-my-bike subject and is likely heavier. Add some mudguards and this could be a great commuter bike, safe enough to lock up outside all day.