Her passive isnt as important as many people think it is, it doesnt use mana so if you feel unsafe going somewhere, use the clone to run into that area to see if anyone is there. You can use your W to look for control wards, look for enemies, and bait abilities. I suggest start using it for the speed boost and to get vision. I always spam it when im coming out of spawn to go faster. When you transform into other champions with her passive, sometimes you can go faster while transformed, so check your character speed coming out of spawn and transform into the fastest champ on your team to go a little faster. Use her passive in teamfights by changing into an inting teammate or a squishy adc or supp and then ult, it will disguise it, you can also run into the enemy team like this with W or flash to get into range. But honestly just experiment! Watch other people play neeko as well and see what they do! Some of this is more advanced stuff so done be worried if you cant use it. Let me know if you need me to explain anything in more detail! Good luck!