what can we use instead of toy to penetrate

Anything smooth, straight, and cylindrical. When I was younger I used the handle of a hairbrush. If you've never done penetration before, you're going to want to make sure what you're using is small; no more than an inch in diameter. I recommend starting with just your fingers to get used to the feeling before you step up to something more. And do make sure it's something you can keep a decent grip on so you don't accidentally lose it. That would not be a fun trip to the doctor.

Try the back of a sharpie(or marker). That works well