Hi Mstrlucky74,
You should be able to sleep on it once it’s fully decompressed.
No I wouldn’t use a box spring (which has springs) for a foam mattress (see the foundation post here and the two links in the second paragraph) but a non flexing evenly supportive support surface such as a foundation or a platform bed that didn’t have gaps between the slats that were wide enough for the mattress to sag into the gaps and gave you the height you are comfortable with would be the usual choice.
Phoenix