How to get good at reading books?
Start one page a day. Yes only one page not two even if you could. Then make it two pages a day in a week's time. Then three pages a day after three more days. Then four pages a day. At this point of time, increase it by additional page every day. Eventually you will end up reading 50 to 100 pages a day in less than 6 months.
Habit stacking works. Make reading paired with any existing habit. Like I'll read before going to bed or immediately after waking up, or after breakfast etc.