You use a fuse tap to connect it to an ignition switched oem truck fuse in your fuse box.
Generally no as the light fuses are typically not ignition switched. If they were, the lights would never work with the key off. Turn signals may work, as those sometimes will not work with the key off but as @SnoFarmer said, a fuse that is higher amperage on a less essential circuit is better. First choice would be one labeled IGNITION, second we usually try the 12v power outlets, third would be things like heated seats, heated mirrors, etc.So it’s safe if I use the turn lights fuse??