This app is used to find your device Via Google's Find My Device service (generally, you also have samsung's implementation as well).
What it does is, in case you lost your phone or someone stole it, you can use Google's service or Samsung's service to track your device, find the last location when it was on etc. Infact you can erase everything inside the phone using this (internal storage affected) change lockscreen password, so no one can open it, or disable the lockscreen entirely.
It is given the device admin permission so that you can perform the above functions easily (only if you log into google or samsung account to do so)
No. Unless you do it. It is meant for using in case of emergency that is if you lost your phone or is stolen. Giving it permission will not do anything, unless you do remote access to it which can be done via your own google/samsung id
