Low power variable optics were the cool thing a year or two ago. I'd check reviews for what's good in 2024, I haven't been paying as much attention lately. Trijicon, Aimpoint, and EOTech are going to be your bomb-proof tested by twenty years of imperialist wars gucci options. Vortex is a solid mid-range. I think Holosun is good, too, but you'd want to check reviews. The Romeo 5 or 6 or whatever is cheap if you just need to slap something on a gun. More money will usually buy you better lenses, stronger housings that resist water and impact, and mechanisms that will keep the dot from drifting off target even after hundreds of rounds and some abuse.

Also - Before you put money down on a red dot figure out whether or not you have astigmatism. With astigmatism the irregularity in the lens of your eye scatters the laser light so instead of a neat clean round dot you get a starburst shape and you can't really use the red dot. It varies from person to person based on the shape and severity of your astigmatism, so some people with mild astigmatism can still use red dots whereas I just can't. In that case you'll want to go with a holographic sight or an etched glass illuminated sight of some kind.

As for LPVOs you're on your own. The one I have I don't think it's even manufactured now. But they're popular because they're almost as good at close range as red dots but you can throw the lever to get 4x, 6x, or 8x zoom with depending on the model. Having a "red dot" for close range and a low power magnification on the same optic is nice. Usually a bit heavier than a red dot, in exchange for versatility.

You should also think about back-up irons. I advocate for having a set of iron sights on your rifle because if everything else goes wrong the iron sights will still work. A lot of people don't bother with them because modern red-dots are very reliable and have absurdly long battery life. It's up to you.