"just got a baby savannah and i have heard many different things from different places."
This is common because so many people buy them, inexpensive imported by the hundreds of thousands every year
"is sand ok to use as substrate and if not what is? the sand i have in there is the calcium sand."
No, sand is a not a substrate, it can be an ingredient in a substrate. You need topsoil, such as what burrowing animals living near river banks live in.
"what besides crickets can a baby eat?"
Small roaches, small meal worms, and baby mice when big enough to. As soon as possible include mice and baby quail in the diet. For now feed as amny crickets as it will eat. Watch for it to stay long and thin when it grow up, you dont want one of those crawling balloons that you commonly see in peoples cages.
"before anyone tells me to do my research, i have."
Seriously, if you did research aside from one lousey source you would know that they are grassland monitors (Africas smallest) that grow to 2-4ft in length (commonly 3ft). They eat almost anything that fits in their mouth, are imported at a rate of around 100,000 a year to the US and most keepers dont have them live very long, or the demand for importing so many wouldnt be there. Spend alot of money and time on a proper cage, its best to build one that has space for a deep dirt to burrow in, some climbing objects, a basking spot that is around 125f as a hatchling, and in a few months up to 135f or higher.
"i was just wanting opinions...i was told they could eat a numerous amount of things. he/she is eating heck out of the small crickets."
There are opinions, then there is helpful advice, this forum in the last many years has seen hundreds of bosc owners come and go because the animal dies from the owners stubborn dislike of keeping the lizard correctly.
"thats another question, how can you tell what sex it is?"
Right now you wont be able to even accurately guess, you need to see secondary sexual characteristics, as with all animals this happens after the animal is sexually maturing.