Decoy blocks and heavy armor are surprisingly effective. You can build small drones with heavy armor and a camera, make sure the camera is fairly situated inside a pit of armor, and then some decoy blocks on the exterior. Heavy armor is REALLY powerful stuff - a lot of youtubers will says "Oh this is only a bit thicker, look how I can blast it with my 8-pack rocket launcher!" or they show weapon designs being used on light armor and shredding stuff. Fact is, large block heavy armor is nearly impervious to gattling gun fire, and can even take several missile shots without worry. Especially if it's 2-3 thick, you become a real tank.
My advice on how to handle NPC ships though...
If you're approaching without a ship, know your angles of attack. When you get to ~1,000m press tab to turn off the HUD, it'll give you a better view of the ship itself and help you see the shape and how to come at it. Turrets have a blind spot, often it's the direct front of the craft.
If you're approaching with a ship, you either want a tank that can soak fire and use of enemy ammo, or you want to be quick and nimble and dart side to side, with enough armor to survive gattling fire but agile enough to avoid missiles.
I generally don't use external view, as I like the challenging realism of first person and cameras. But if you are going third person to do things, you can take your starting ship and put a sheet or two of heavy armor on the front. Use it to just ram the enemy ship. You can often aim and take out turrets, or just flat out ram it and break it in half, then go collect the half that isn't armed and salvage it.
If you're not opposed to using mods, armored cameras are nice for being more durable, because turrets prefer to fire on exposed components more than just armor. "Artificial asteroids" is also fun, it adds armor blocks that look like stone, for building covert bases, but they only cost gravel to put on small ships, and large ships take like gravel and a single pipe, so they're SUPER cheap and usable as disposable armor, in case you don't want to use up steel on armor plates. Other options like railguns and battlecannons have longer range that turrets and can be used to snipe the ship from range, either to hit the turrets or to try and peg the reactor.
EITHER WAY, checking the wiki and looking at the ship models is probably the best thing you can do. Just knowing their shape and where the turrets are is often enough to learn how to approach them in suit and take them over.