It might be tempting to think that "it's easier to have kids in your 20s and early 30s than later" is just something annoying relatives who want nephews and grandkids without doing all the hard work say, or worse something the creepiest men on the internet say just before demanding child marriage be legalized.
But, it's also kind of true.
If you want to have kids don't dwaddle if possible. IVF is no fun. It sucks. Stop trying to own a house and have the perfect job before you have kids.