They're all have very similar meanings and can often be used in the same situations. ''Would'' expresses that an activity was routine, typical behavior, frequently repeated. ''Used to'' expresses that an activity was a past habit, it occurred at an earlier stage of life but not now. It focuses on the habit, not duration or frequency.

In regards to past habits, "used to" is used for typical behaviour, and "would" is used for predictable behaviour. The basic difference being that a habit described with "would" indicates that it didn't always happen regularly.

'Woude' is like-if you had more time you woude have had better grades in school 'Used to'-You used to have better grades in school Woude is like somthing in the past that you didn't do or didn't have time to do. Used to is like in the past you did or liked somthing but now you don't. I hope you understood me