Should I use fish eye eliminator with my acrylic enamel when I paint my truck this weekend? Heard this was a good idea so justr wanted to make sure :D

If you have done your prep work right you shouldn't need to.
If I remember only thing fish eye eliminator is just silicone that you add so if you have any on your vehicle it won't react.
Before you start your sanding just wash your vehicle with dawn soap. It cuts grease and wax before you sand.