Asteroids are not a concern. Real asteroids are not like the movies or the classic game. They are spread far apart. Even in the main belt between Mars and Jupiter they average ~1,000,000 km apart. There are a lot of them, so by happenstance you could pass relatively close to one, as New Horizons flew by an asteroid at a distance of over 100,000 km on its way to Jupiter and Pluto. (Or you could expend a potentially significant amount of fuel to deliberately fly by one at a closer but still-safe distance, as Galileo flew within 2,400 km of 243 Ida on its way to Jupiter.)

Micrometeroids are somewhat more of a concern, but mainly in low orbit around a massive object like Earth or Neptune, much less in deep space. (Neptune has faint dusty orbital rings.) For that, something like a Whipple shield would greatly reduce the risk and damage from micrometeoroids and other debris up to ~1 cm in size. (Earth has both natural and artificial debris orbiting it, so shielding is especially important for the ISS, which is spending decades in low Earth orbit.)