https://zkillboard.com/kill/101697948/
Okay. Let's talk about this.
First, let's talk about what happened. You were in a Low-Sec system, ratting in a belt, and got attacked. Treat Low-Sec as a completely different thing than High-Sec. The 0.1 difference between 0.5 and 0.4 doesn't mean that it's that much more dangerous, the same amount more dangerous as 0.5 is than 0.6. In terms of the danger of other players, think of everything from 0.5 to 1.0 as one category of danger, everything from 0.1 to 0.4 as another category, and everything from 0.0 to -1.0 as a third. 0.5 systems are, in most regards, as dangerous as 1.0 systems. 0.4 systems are pretty much the same as 0.1 systems. 0.0 systems are pretty much the same as -1.0 systems. This is with regard to danger from players.
There are some exceptions to this. The main one is that in High-Sec, the system security rating determines how fast CONCORD will respond, so if you get attacked by suicide gankers, they have much more time to kill you in 0.5 than 1.0, but this isn't something that you should ever rely on to keep yourself alive. It really only makes a difference with hauling in freighters and deep space transports (particularly freighters), and if you're hauling cargo, it's much safer to rely on scouting the route ahead for safety.
Within each of those three categories, the danger of specific systems depends on geography more than the system security score. One of the big dangers in a Low-Sec system is if it is an entrance system from High-Sec. That's what Covryn is. Many of those systems have the entrance gates camped to catch people coming in from High-Sec who have not yet learned that the High-Sec/Low-Sec boundary is the most significant transition between types of space in terms of how dangerous they are.
Within Covryn, you were ratting in a belt. This means that if someone knows that you're in the system and undocked, it is very easy to find you via directional scanner and warp to you.
How to prevent it:
1. If you undock outside of High-Sec, assume that anyone not confirmed to be friendly is hostile. If you're not ready to fight someone, avoid that person. Keep the local chat channel visible when you can to see if any other people are in the system.
2. Develop an idea of what you're doing, where to do it, and what ships to fly for it. This could be as simple as "I run missions with a Vexor because I can afford it and drone ships tend to be good for PVE), or it could be "I will use this particular fit for my Sleipnir for solo PVP roaming." If you're going into Low-Sec space, always keep in mind that it is inherently dangerous space and often ends up being more dangerous than Null-Sec. If you're going to do PVE activities in Low-Sec, keep in mind that the people who come across you will think of you as food. Think about what you'll be doing in there, and whether or not it's worth the risks of Low-Sec.
3. Make sure that your ships are fully fit for the purpose that you want to use them for. In general, if you have to leave a slot empty, it's best to leave a high slot empty once you've filled all of the hardpoints for the weapon type that you're using. I see that you filled the Vexor's utility high, but left one of the mid slots empty. Depending on what you're trying to do, you can find people who can give you some good advice. My PVE tends to be mining/industry, so ratting is outside of my area of expertise to give you tips on how to fit ships.
4. When you're doing something in dangerous space, be in voice with people. E-Uni pays for a really nice Mumble server for its members to talk to each other. This can be both social comms and fleet comms for coordinating in-game activities. Covryn is right next to Stacmon, where you can very likely find other Uni members available to help you do stuff.
Like UU said, I wouldn't worry too much about getting revenge. Don't take it personally. If you want to get into PVP (and potentially shoot this guy if you come across him again), E-Uni has opportunities for that. You don't need to be the most experienced and skilled person to do well in a fleet. Even two or three people roaming together will massively surpass their combined individual capabilities.
If you really do want to something akin to revenge, I have an idea. You're clearly capable of sitting in a Gallente cruiser. If you fit one for maximum hull buffer (damage control and bulkheads in the low slots and rigs, mainly), with MWD, warp scrambler, and stasis webifier, along with an energy neutralizer in one of the high slots, you can sit in a belt in Covryn as bait while working with other Uni members in Stacmon. If someone brings an expensive frigate like this Succubus (in addition to being an expensive hull by frigate standards, the pilot was using faction lasers which each individually cost around as much as a Tech II frigate, and his recent losses seem to have a few faction and abyssal modules) or maybe even a Kikimora, an expensive destroyer, your bait ship will look like food, but you can use it to hold him there for other Uni members to come in from the next gate over in Stacmon, and you'll help them kill something.
If you want revenge on this specific guy, I don't know of any real way to guarantee it. Your best chance is to join Uni fleets which form out of Stacmon and go on roams, potentially come across him and kill him.