Have you chosen white for your walls yet? If not, you will soon (because white walls are where it's at!) and if you have there's a 95% chance you struggled to find the perfect white. How do I know this? Because whites are insanely tricky! They can be easily swayed by other elements in the space, have random undertones pop up at unexpected times, and can be an overall very frustrating decision to make because they tend to all appear very similar on a paint chip.
Here is my roundup of whites that I have tried, seen in multiple spaces, and had success with. Warm spaces call for creamy whites like Swiss Coffee or Dune White. However, if your home has a more modern and cold vibe, then I recommend choosing a crisp white like Decorators White. Finally, if you tell me that you literally want a true white, I would introduce you to Chantilly Lace.
As for your trim colour, I recommend you do the same colour on your trim or get the paint tinted at 50% lighter or 50% darker than the colour you've chosen. This keeps it clean and consistent. Plus your trims should be in a pearl or satin finish so they have a bit of gloss, and this always makes them appear as a slightly different colour than the walls!
I hope this helps! Here are some pictures of the winners:
Decorator's White from Decor Pad
Swiss Coffee from Brunch at Saks
White Dove from Decor Pad
Chantilly Lace from Studio McGee