Make your planet hard to spot, and uninteresting. Play the odds.
There's a lot of planets.
The Milky Way is estimated to have over 100 billion stars each with at least one planet. If you had 1000 ships each visiting a star per day it would take 275,000 years to visit them all.
Space is big. Planets are not.
Space is really, really, really, astonishingly, mind-bogglingly big. On that scale planets are not. 99.9% of the mass of a solar system is in its star, that 0.1% is left over for planets. Rocky, Earth-like planets are particularly small. We live a small crumb of the universe; a peculuarly wet and warm and stable crumb, but a crumb.
Planets are hard to see.
Planets emit no light of their own, only reflected starlight.
Currently we spot planets which are very large and/or very close to their star. Large, close planets make their star wobble just a little bit, and we can see that if the wobble is large enough. Or, if their orbit happens to be in line with the Earth, we can see them as they pass in front of the star if we happen to be looking just then.
Even if spotted, someone or something then has to pay particular attention to it out of the 100 billion planets.
Your "secret" planet.
Even with advanced technology, the fundamentals remain: out of the hundreds of billions of planets, someone has to spot and take an interest in your planet. Don't give them a reason.
Pick an area far away from civilization centers which would have good star-scanning capability. Perhaps on the opposite side of the galactic center. In that area choose a massive star with a large habitable zone and nothing of particular interest in the system. Pick an uninteresting rocky planet at the far edge of the zone. Such a small, far away planet will not cause its star to wobble, nor will it be likely to be caught in a transient. This minimizes the chances it will be spotted at all.
Control your emissions to avoid any tell-tale traces of human activity in the atmosphere which might suggest that it's occupied. Excessive amounts of methane, short-lived radioactive material, and so on.
That's about it. Depending on your technological level, it's not necessary to hide underground, or avoid having satellites in orbit, or otherwise mask your surface and orbital activities. They can't be detected from a distance, and there's no reason for anyone to visit for an up close look.
Have a cover story.
Just in case anyone does visit, have a cover story and a reason to keep yourself a secret. You're an independent, quasi-legal mining operation and you'll pay handsomely (but not too handsomely) if the interloper would kindly keep quiet about their operation.
After they leave and their ship is well away from your planet, maybe their ship has an "accident".
...would there be a way to make the planet look like a black hole from any sensors/scans that would fool people from wanting to go to that area of space?
Not without getting into absurd technology.
Unlike in the movies, black holes aren't particularly any more dangerous to get near than any other object of a similar mass. If a star turns into a black hole you don't suddenly get sucked in, it has the same gravity as before.
Presuming you can't change the mass/gravitational pull of the planet, it has to be a planetary mass black hole with the same gravity as a planet. Which is to say not much on an astronomical scale. It would pose no danger to anyone entering the system.
Then there's replicating the key aspects of a black hole: gravitational lensing and the event horizon. A black hole the mass of the Earth would have an event horizon of about 1 cm meaning any light within 1 cm cannot escape. Light which gets close will be bent. If you can replicate this, you effectively have planetary cloaking technology.
Very large black holes may have accretion discs. If large and violent enough this might be something space-farers want to stay away from, but again, this is a tiny black hole.