soft brake pedal / excessive brake travel
I’d get that looked at. Soon.
Low or old brake fluid or possibly air in the lines. If it’s low fluid there could also be a leak somewhere.
Check underneath the car for brake fluid. If you find some, don’t drive it, except to the shop. If you don’t find any, then the brake fluid probably needs to be changed. The symptoms you describe seem like old fluid with water and air in the lines. Brake fluid absorbs moisture from the air, BTW.
A bad brake master cylinder can cause that.
Yeah, and if it’s a bad master, it’s only going to get worse until the brakes stop working at all, so you need to have this looked at immediately.