Then process it ferther, there is node called “Sign” which returns either 1 or -1 depending of number sign you inputing.
For the future if you don’t have such sign function you can do this mathematically by x / abs(x), x/x always gonna return 1 but if you make one of them absolute number (always positive), as multiply sign law say, if numbers signs are different the output will be negative number. so if x is negative 2nd x gonna be still be positive and division gonna return negative number because signs will be different.
As for random on spawn, you can do that by placing you module on particle spawn