So just recently my upper right brake started making a clanking noise (like metal hitting) when im at 15-20mph braking, and a high pitched squeaking when it's 10-5mph.

I literally changed the brake pads because thought it was it, but still persists, the rotor looks really sleek, but so does my other side and it doesnt make a noise.

idk what it is, i looked at the caliper and nothing looks wrong with it, my friend said it looked like a piece of it was loose and put this purple grease stuff adn it worked for 2 months or so.

Any suggestions? i've googled everything lol

If it is squeaking or squealing under braking, not just riding around, then it is the friction material of the pad making noise against the rotor. There isn't much you can do about that long term. If you pull the brake pads out and sand them with scotchbrite or a scouring pad you can put some texture back on them and knock some of the glazing off. A wire brush will work, as will the textured finish on a concrete driveway. By knocking the glaze of it might stop squeaking for a while.

Only glaze I like is on my dounts.

what department you with officer?

Take it to a professional. Taking short cuts on brakes is not a good idea.