Press the pencil button and you will get options

I didn't work 😭😭😭😭
I'll just wait forna stylist

Oh I'm on a tablet but I'll try

1-you have to press the button of a pencil
2-Then down there you can see some different pencils: square, spray and the normal one.
3-If you want one, just click on the one you want and you're done.
By the way, I don't know how yours is because I draw on a phone, it's different on other devices