Does anybody know this animated series?

OK. I know it might not be a movie but I remembered an animated TV show I watched as a kid, on TV, so it was made quit a bit before 2015, because that is the last time I actively watched TV and I wasn’t a kid 2015.
The story is kind of 3D animated, like Trollhunters but lower quality because it was made much earlier. The main characters were a few kids that protected Earth from aliens and worked for this big space organization. They equipped some costumes and like in movies, a half-transparent visor was enough to make them unrecognizable. I remember there were at least 2 boys and 2 girls. One of the girls had black skin, the other was blonde. Their secret base was in the blonde girl’s backyard because she and her grandpa were actually aliens. I also remember an episode where a statue turned out to be a petrified alien that came back to life but was scared of pigeons for obvious reasons. Another episode was where their no-alien-life-believer teacher was almost married to an alien lady, the teacher denied all existence of intelligent life outside of Earth. Finally, another episode involved one of the boys, a bit of a daredevil, flying through a tunnel that brought him to the future and they had to prevent their discovery because the Earth would have been destroyed. It was aired either on CN or Disney, we had no other channels.

PS: Sorry, but I just remembered another animated TV series. It was about teens fighting aliens, some of those teens were aliens, their commander was a gold fish that once morphed into a fish-man. Their enemy was an evil alien that wad disguised as a chihuahua and the principal was his servant and only one that could understand it. Weird, I know.