what is the translations of:

´be my valentine´

think it is: sevgilime olmak?

Tesekkur ederim

As a learner I would try:

"Sevgilim ol" ("be my beloved one" - "ol" is an imperative form of "olmak")

"Sevgilim olmak" is the infinitive form - "to be my beloved"

but better wait for someone more advanced or native speaker.

 ´be my valentine means " Sevgilim ol " (be my lover,my valentine)