Hello bonsai community
I just started with my journey with bonsai and would like to learn more than creating little trees but also making my pots. I was wondering if cement pots are capable material and if so what sealer can i use to prevent ph or chemicals yo affect soil?

You cannot make pots out of cement, you will need concrete.

Bonsai by the sea on youtube have a lots of content on making concrete pots. He do not use any sealer.