Paula 说:
Paul has a Suzuki something 500
That doesn't really give any info though, because these are both Suzuki "something" 500s:
Anyway, the things you'll want to consider (especially if it's your first bike) are:
[*] How much it will emotionally pain you (and your wallet) when you drop it. You
will drop it. You might want to start off with something second-hand and definitely invest in crash-bungs.
[*] How much your insurance will cost you. Being female, it will be less than a guy pays, but it could still be quite a bit. The bigger the engine and the sportier the bike, the more it will cost to insure. Also keeping it on a porch is not a great idea. It will get stolen within 5 minutes. And an unsecure parking/storage will also hit your insurance hard.
[*] Whether you are using it for fun or for work/commuting. If it's the latter you'll want to avoid the sportier models and go for something with decent fuel-economy. The Suzuki GS 500 is a good example of a simple, no-frills naked bike that will do decent fuel economy on longer haul journeys. Alternatively if you're just nipping around a town/city don't bother with anything that big; Yamaha, for example, do some great little 125s (and I think even some 250s) that have excellent maneuverability an they will run forever before needing refuelling. Take a look at what's recommended as a city courier bike and you can't go wrong. But if you're getting one purely for pleasure then you have to consider...
[*] Position and comfort. A cruiser should be more comfortable (unless you have an atrocious one) than a sports bike for long journeys because it takes the pressure off your wrists and automatically puts you into a more upright position. But not everyone likes the feeling of sitting back with their legs out in front of them; I struggled like hell with my cruiser's position, and only after trying a GS500 did I realise I needed something with a more neutral position, hence my Kawi ER6.
[*] Parts/repairs. You live in Europe so shouldn't have any problems getting parts for any kind of bike you want to get (unless it's some dodgy Chinese import; avoid those) but some will undoubtedly be more expensive than others. Same as pretty much anywhere, you'll find parts for Triumph, Ducati, Harley, etc, more expensive than the "Big Four" Japanese models (Suzuki, Yamaha, Kawasaki and Honda) but even there you will find some variation, and the general consensus is that Hondas and Yamahas are a little more reliable than Kawasakis and Suzukis (unless you get into the very high-end sports range, where they're more comparable)
But that's all the advice I can really give without knowing what you had it in mind for.