Hey Sara, here a lot of clothing for learning vocabulary or maybe used it for work or at home : https://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Dfashion&field-keywords=clothing . Enjoyed !
I usually call the clothes I wear at home "loungewear". You also have "sleepwear" for stuff you sleep in.
As the "Athleisure" style has been showing up in my country, I guess nowadays sleepwear in public would be more acceptable, with the right touch.