It wasn't perfect, nobody cared. There were dandelions, there was some clover.
If you can bear to tolerate the fact that your lawn isn't going to look like a putting green, you can do literally nothing but cut it and perhaps water it if your climate requires and be done with it. If there are plants you don't want in your lawn, take them out with your hands or a hoe. If you can't be bothered, then be happy with what you have. If your lawn really can't grow without intense chemical assistance, then maybe don't have a lawn.