I've been on steroids for 18 months and after GCA investigation am now down from 40 mg to 18 mg daily. No pain but walking especially in the morning is stiff - can be penguin like- and standing for any length of time also a problem. Both make planning trips out very difficult.
PMR & Steroid side effects: I've been on steroids... - PMRGCAuk
PMR & Steroid side effects
Sounds to me as though your reduction might have been a bit fast, because pred should ideally eliminate that stiffness. Could you consider at least stopping at your current dose, if not increasing slightly, until any residual inflammation is cleared out?
The other issue is the muscle weakening which pred causes, and there's no way around that, I'm afraid. Just be kind to yourself, try to avoid standing or walking for long periods of time. Several short walks rather than one long one will add up to the same thing at the end of the day, but the rest and recovery spells in between will help you. Eventually as you wean off pred this will improve, but even down as low as I am (around 3.5) I am still not as strong as I was pre-pred. It all takes time, and we just have to accept there's no rushing our progress.
So when planning your trips out, do your best to include a stop or two, just to have a snack in a cafe, sit in a park, whatever is feasible in the circumstances. Lengthy hikes might be out of the question for you this summer.