To an extent, the answers you get depend on your own intentions. For example, you mention weddings, but are you wanting to get into *serious* wedding video, or just a few gigs? Because if it’s only a one-off, you’re better off renting specific gear to each shoot. There’s a break-point in that, if you rent lights more than about 4 times, and still plan to keep doing this, you’re better off owning them outright. But starting out with rentals lets you try a lot more options and learn what you like and don’t like – without having to eat the entire cost of something you bought and then don’t like or can’t use.
Shooting inside a house for dramatic lighting, something that becomes very handy is a long telescoping bar called an “auto-pole”, which is a portable lighting truss that can hide near the ceiling and hold your lights up without floor stands getting in the way and in the shot. Matthews and Manfrotto are sources. The China ball will be a versatile tool there as well as simply bouncing light off walls and the ceiling to bring up the overall levels.
Music videos are such a broad topic, there’s little point in giving advice until you provide a script/breakdown of the specific scene and the intentions.
I’m a generalist: I do a little bit of everything.
I have a pro lighting kit of tungsten-halogen-based lighting gear that’s been in weekly use for decades: so, even though it wasn’t cheap to buy originally, dividing the cost into the time you used it, it was the cheapest thing ever. Not as cheap as buying something more than once because it broke or was otherwise inferior the first time.
Now, old tungsten-halogen lights have arguably had their day, and LED is the New Hotness. That said, there are places like Wedding shoots where you might need very long throws, where the old hot type lights still have more power and reach than comparable LED. Lots of pros are selling off their old tungsten kits now to get new LED kits; that’s also an opportunity to buy quality used gear that still has plenty of life in it, but the depreciation and amortization’s all been taken care of by someone else for you. If they still do what you need, are high quality name-brands with good support, used pro gear is a good value.
But say I didn’t convince you yet…
If you are buying LED lights today, to start your kit, they need to be capable of switching between indoor and outdoor color temperatures, preferably with a smooth, continuous adjustment, and dim without adding flicker to the shot – this is a key difference between cheaper LED and the right stuff. Adapting tungsten color temp lighting to daylight involves color correcting gels that rob the lights of more than half their power. So if daylight is where your projects mostly live, consider that and you may prefer daylight LEDs or even an HMI light like a Joker.
You can’t afford everything you really need on 500 euros. I’d conservatively say you should triple that as a start… but you need not buy it all in one jump. You’re going to have to build up your kit a piece at a time, over a long time. Some pieces, you can make DIY in a thrifty yet functional way. YouTube photography sites show hundreds of ideas for this.
Personally, I would start from a classic three-point lighting kit, then keep adding modifiers and accessories as you go. Extra stands and reflector boards are an early step but very useful and inexpensive. Get some diffusion. An umbrella or two, and a couple of softboxes would be next. Gobos and cookies and additional stands and arms to hold reflectors and bounce cards are something you want sooner rather than later. Some black cinefoil. Clamps and other grip gear. A couple of variable dimmers are nice to have. A big frame and stands for a “butterfly” will be handy for wedding shoots and outdoor things, to create soft shade from direct overhead sun… Then other, purpose-chosen pieces, like maybe a variable-color LED light, the kind used by club DJ’s – these can be handier and more efficient than buying sheaf’s of colored gels for making colored backgrounds. A “China ball” and a pole to hang it from… Actually, a video pico- projector, driven from your phone, can be a very useful lighting tool to throw patterns and colors onto many surfaces. But it will need a way to hold and aim it. Those very tiny cube-type LED lights, running on batteries, can be super-handy as little accents…
Every job you bill, you need to build in a little fee towards buying the next piece of gear. Also try to groom some contacts in the pro video rental business to bring in the extra support as and when you need it. These relationships need to be built up *before* the day you suddenly need a big favor on a shoot day.