soler vs acostumbrarse
Soler means 'to usually do'. Acostumbrarse means 'to get used to'. English uses 'used to' for both ideas and learners tangle them.
soler
To usually do something — a habit expressed with soler + infinitive.
Suelo levantarme a las siete.
I usually get up at seven.
A routine. Shorter and more natural than 'normalmente me levanto'.
Aquí no suele llover en verano.
It doesn't usually rain here in summer.
Works for general tendencies too.
Solíamos ir a la playa.
We used to go to the beach.
Imperfect soler = used to. Only exists in present and imperfect, rarely elsewhere.
acostumbrarse
To get used to something, with acostumbrarse a + noun or infinitive.
Me he acostumbrado al frío.
I've got used to the cold.
Getting used to a new situation. 'Estar acostumbrado a' = to be used to.
No me acostumbro a madrugar.
I can't get used to getting up early.
Acostumbrarse a + infinitive.
Te acostumbrarás.
You'll get used to it.
Reassurance with the future tense. Very common.
Tricky bit
English 'I used to' (past habit) is 'solía' or the imperfect, while 'I'm used to' is 'estoy acostumbrado a'. Don't use acostumbrarse for past habits — 'acostumbraba' exists but sounds literary.