I would recommend starting out with HIIT only twice a week, maybe even just once, depending on various factors. Sprinting can tear you up (literally) if you push too hard and don’t give yourself ample recovery, especially when youre first starting out. But, things like jump rope or bike riding shouldn’t be as bad.
Doing them on separate days is ideal, so MWF you can do strength training then T The HIIT, maybe with a bit of hand balancing after for general training purposes. Personally if I were to do them both the same day I’d probably do strength training first then HIIT later in the day, and I wouldn’t do a heavy leg workout the same day as sprints…or even in between sprint days. On that note, if you want to do a heavy leg workout save it for sometime after your HIIT for the week.