Crickets eat all kinds of garbage so if you gutload them- feed them nutritious food so it's in their belly when they are eaten. Basically make sure the crickets are healthy for the fish. Healthy food might look like cichlids pellets
Welcome to the Fishy family.
Oscar's are a great fish if taken care of properly. They are really personable often being called "wet puppies".
I like you started with a little tiny inch and a half fry.View attachment 1326447
Now a year and three months later I have a big beautiful eleven inch monster. View attachment 1326448
Oscar's are big dirty fish, as you have seen already a lot of food comes flying out of their mouth and gills when they eat. This helps to turn good water bad fast. Also being such a big bodied fish they urinate and poop a lot. All this adds up to having to do lots of big water changes. I do fin level water changes every other day.
You will have to pick either the Oscar or the others. In a few months that Oscar will out grow them and turn the currently peaceful existence to a blood bath. View attachment 1326449
Case in point, she peacefully lived with them barbs for 8 months till this. As with all fish if it fits in it's mouth, it's food. So what ever you house in the same tank must be bigger than the Oscar's mouth. And if still growing must keep up or like the Roseline shark, will be dinner.
They are not that hard a fish to care for really, just have to do them water changes, feed it a good quality pellet, with treats here and there, and in no time you too will have a monster wet puppie.
You can check my thread here. It's the whole trip me and Toni took to get where we are now. You could learn from some of my oops moments and not do the same
https://www.monsterfishkeepers.com/forums/threads/toni-and-nemo-my-albino-oscars.690421/
Any recomendations for pellet. Ive been using bug bites cichlid formula