"used to "
"Used to" expresses the idea that something was an old habit that stopped in the past. It indicates that something was often repeated in the past, but it is not usually done now.
"Enda used to study English" ( It means he is not studying it anymore in the present time)
"She used to eat meat ,but now she is a vegetarian."
( In the past it was an old habit ,but she stopped it a while ago in the past and is not doing it now.)
"to be used to doing something" means regard something as normal, not unusual and be familiar with it .
" He has lived in England for over a year so he is used to driving on the left now."