In English "sometimes" and "at times" are largely interchangeable, "sometimes" is more commonly used in casual speech, and "at times" can add a slight emphasis or formality.
"Sometimes" can be usually placed at start, middle or end:
"Sometimes I listen to music" or "I sometimes listen to music" or "I listen to music sometimes" are all okay.
"At times" is mainly used in a formal setting:
"At times, the workload is overwhelming"
So generally just stick with "sometimes", it is a more general term and used in general conversation.