H4 or F1 better before coming to US

Hi

My fiance is a H1 B holder.as in H4, i wont be able to work.

which option is better to pursue a degree to work? H4 Cos or F1 student visa.

i would like to know that coming to US through F1 or H4 better? F1 chance of visas getting approved is more?

F-1 is for studies and not work. H-1 is for work.