easy baby gym build i made for my newborn nephew. you need 5x 24mm diameter x 70cm length sticks (i bought cheap readily available broomsticks and cut them to size)
you can hang fun things for the baby to play with from the baby gym. my mom made very cute crocheted animals.
included in the files are a version with the name liam embossed in it, and a version without a name embossed.