All garments are laundered prior to purchase, unless the fragility of the item does not allow. Shall a garment need laundering later on, I recommend washing all vintage and handmade pieces by hand to prolong their life. Treat stains immediately, use delicate hands and soap when washing, roll dry in a towel, hang. Trusted dry cleaners can also be great for silks, rayons, and lined pieces. Feel free to reach out with any specific questions.
I recommend storing most pre-1950's garments and anything delicate as flat as possible, in drawers or in boxes, not hung. Archival boxes and archival, acid-free tissue paper are the best storage methods, though just the tissue paper in plastic bins can work as well. This will help preserve the strength of fabrics and seams. Keep pieces out of the sun to prolong their color. Treat them well, like your children.