Amanda and I built a simple box for a raised garden bed. Its about 8x4ft and 12in tall. It held a lot of dirt. We bought 1 yard from the local city compost place and it took almost all of the dirt to fill it.
We used this guys design from his youtube video. It’s really just a big box with some 2×4 rails on top.
The little plants need to grow a little more before being moved.