When you move into a new home, whether into someone else's home or a new place altogether, there's a brief window during which you have a unique superpower: the ability to see everything clearly. Use your power wisely, my friends!
In many aspects of life, we are discouraged from making snap judgments — but when you move into a new home, those knee-jerk reactions might just be your greatest ally. You will find yourself able to walk into a room and see that the table position is awkward, there are far too many knickknacks, that that one lighting fixture sticks out like a sore thumb, the paint color is neutral but somehow nauseating, and the furniture arrangement makes you feel claustrophobic. It's crucial to make note of these feelings right now, because after a few months or weeks or even days, you'll probably no longer be able to "see" the issues. We get settled in, our brain gets accustomed to things looking a certain way, and it all kind of blurs. You might find yourself feeling stressed or uncomfortable in your home, but it will probably be a vague sort of feeling, rather than a clear-cut "This carpet makes me want to scream!" A dramatic reaction, to say the least, but at least it's one you can do something about. It's much worse when you want to scream but you don't know why..
So am I advising you to waltz in and change everything right away? No, and definitely not if you're moving in with your partner or roommates. They probably won't take too kindly to you pointing out everything that bothers you and/or rearranging all their stuff. Living with things, though it can dull your fresh eyes, is necessary to understand how everything works together, and how it would work for you. Instead, I'm recommending you take notes — extensive notes. Write down everything that bothers you, with specific reasons and ideal solutions. Don't just write "light fixtures", write "Kitchen light fixture: too low (bump head), fills with dead bugs, glaring light — replace altogether. Bathroom light fixture: nice hardware, tacky shade, horribly unflattering light — get new frosted shade and daylight-balanced lightbulbs." Then once you've lived there long enough to feel confident in making changes (and you've saved up enough money), you'll have your notes to guide you. Who knows — your opinion might have changed by then, but at least you'll be well-informed, by your superpowered past-self.