how come profiles & device management isnt in my iphone settings?
trying to download something and i need to have profiles & device management in my settings to do so.
That sounds extremely dodgy to me. Device profiles are only useful in certain situations and certainly NOT to ordinary consumers. They are of interest in corporate environments (in which case talk to your sysadmin), and to developers.
They are also of interest to thieves as that are pretty much the only way to 'hack' your phone ('hack' might not quite be the correct term there but it conveys the right information).
If you are following a guide that involves installation of profiles, and it is not from a corporate sysadmin that you trust, do NOT install the profile. That graphic certainly does not appear to be from corporate documentation.
The menu option will not appear if you do not have any configuration profiles stored.
Some more information here: How to delete an app that has a configuration profile on your iPhone, iPad, or iPod touch - Apple Support