If you are struggling with your mobility and you don't yet have a consistent movement practice that supports it, the Start Small principle can be of great value. This principle is simple: start by learning one exercise that you can realistically practice daily. Ideally, this exercise should address a target area or priority. For example, if you have trouble with stiff shoulders, choosing scapula circles as your exercise would address your main trouble area with one exercise. You could do 10 reps of scapula circles 3x/day.
By applying this principle you effectively take action on increasing your mobility and developing a regular movement practice. Once this initial step has been taken for several weeks, you can proceed gently by adding in one more exercise that you can realistically practice daily. Eventually your practice will evolve into something more and your mobility will improve.
As a good friend once told me, "You can't start without starting".