We use 'used to do smth' when we tell about the past events. For example, 'When I was a child, I used to go skiing'. It means that earlier I did it, but now I don't do it anymore. If you 'are used to smth, you are accustomed to it – you don’t find it unusual. For example, '5 years ago I was afraid of driving. But now I am used to driving'.

(Used to) is used to express past events that happened in the past, the equivalent tense is simple past. It's used in the following cases: 1- To express events that happened in the past on a regular basis: "I used to play football on Sundays." 2- To express past events that happened under certain circumstances or conditions: "He used to take long walks after rain." 3- A particular identity or profession that represented someone/something in the past + be: "I used to be a cop/ This place used to be a stadium." As for (to be use to), it has two types: 1- To be + used + to + verb +ing is used to express habits: I'm used to studying while listening to music. 2- To be + used + to + object pronoun (like me, him, it us etc./proper noun or noun clause (like John, Linda, Parisian food) is used to express that you're accustomed to someone/something and that you find them normal, familiar or pleasing: I'm used to it, they're used to cold weather etc.