My definition of "self care" is taking time for yourself away from other obligations, like work, kids, etc. to do something that improves some aspect of yourself, like exercise, learning something new, preventative medical care, mental health, etc. It needs to have a specific goal and lead to some larger benefit than just enjoying yourself for an afternoon, otherwise it's just "goofing off."

For you, that seems to be decorating your home. You seem to value expressing yourself in that way to start conversations or just be around familiar surroundings. And that's awesome!

I personally don't find value in that, and having a spartan home is an expression of my personality as well. I may have a few things I find value in, but they're usually utilitarian and not really decorations. I value my privacy, so the only people who know much about me are people I choose to share that with. I find value in minimalism, and having decorations and whatnot goes against that. So for me, self-care is eliminating stuff I don't value, using the things I do, and pursuing longer term goals (exercise and whatnot).

Make sure that your form of self-care helps you achieve your goals. If that includes getting into a relationship, that self care should improve your chances to meet new people. Maybe that means updating your wardrobe, exercising and losing weight, of anything else that improves your self-image and confidence. Beyond that, you need to make time to actually meet new people. But maybe a relationship isn't your goal, so your self care could look very different.

Self care should be part of your plan to reach your goals. If it's not helping you reach your goals, it's not self care and just a waste of time.