The first thing I do with any cream dress is hold it up to the nearest window, or if there isn't one, tilt it under the shop lights and squint. You're checking two things at once: whether the fabric is lined, and whether it turns see through the second there's proper daylight behind it. I learned this the hard way standing outside a chemist's wondering why two strangers were looking at my legs funny. The dress was gorgeous on the hanger. Under the strip lighting inside, it looked perfectly decent. Outside, in actual sunshine, it told everyone exactly what underwear I had on.
Cream is not a colour for messy days, that's just the truth of it. Red wine, tomato sauce, a leaky pen in a bag, any of it finds a cream dress like it's got a homing signal. It's also unforgiving about what's underneath, so nude or cream underwear becomes non negotiable, and you want to check the side seams and the bust lining properly before you buy, because a cheap lining will gape or show every seam allowance through the front. For shades, the stark fridge white end of cream is the hardest one to live with, it photographs harsh and makes most skin tones look a bit grey by comparison. Softer, warmer creams, the oatmeal and buttermilk end of things, sit much better against actual human skin and don't scream at you from across a room. As for wearing it in, cotton and linen cream dresses soften up lovely over a few months of washing, but they also go a bit grubby looking under the arms if you're not careful, that faint yellow tinge that creeps in from deodorant and heat. A cool wash, inside out, and skipping the tumble dryer entirely will slow that right down. Tumble drying on any heat is basically how a cream dress turns into a slightly dingy off white dress within a season, and once that colour shift happens there's no bringing it back.
Line dry them out of strong direct sun too, because the opposite problem exists, patchy fading that leaves the dress two different shades depending on which bit faced the window. The one mistake I'd actually tell you to avoid is buying cream under shop lighting and never checking it anywhere else before the tags come off. Shop lighting is kind to everything. Daylight is not, and daylight is where you're actually going to wear it.