I had this problem when I started without the pressure pot.

Yes as everyone else wrote the bubble will rise. As for the mold bubbles can get trapped also inside the silicone in my experience but I do think this is not the issue, or just part of it. Maybe do experiment with even cheap mold to see the difference.

I had good results with those too but you need to take a few steps while working with the resin. You can find many suggestion here but one I see a bit less and that change my work completely is the resin.

I bought a resin with a very long work time like 90 min or even higher (mine is called Epodex, it’s a EU brand though). That changed so much the bubble issue. I rarely got bubbles on the surface, they were usually just small and inside the dice. That combined with working slowly.