Ask for NO colour corrections when you upload your files to get them printed online!
The printers could over correct for a photo it deems too dark, or light, or if it contains too much of a certain colour. This is a problem if the photo is not equally light/dark, etc. You could end up with images that have a blue or orange tinge accidentally. Computers/artificial intelligence are not always smarter.
If you need help, don't hesitate to contact me.
If you're interested in creating a gallery of images for your wall, use a large piece of wrapping/butcher paper, tape it to your wall and measure the space for images and placement. Then you can easily see which size prints/canvas would look best in the space.
There are nice handy tools online that give you a template of image sizes to play around with which will make ordering a grouping much easier.
Backup your images on a hard drive/thumb/flash drive or on the cloud/Amazon Photos. I do keep your images for a year or two, but please don't count on my hard drives NOT failing. It has happened. If you save it to your phone the images may be resized, so make sure you save your full sized files.