@MickeyWy
Welcome to the expat.com forum, and good luck with your property (and country?) search!
As you're probably aware, as a citizen of an EEA country, you enjoy the EU's "freedom of movement". This means you can relocate to any EU country, for any reason, with minimal bureaucracy. So that's one less thing to worry about! :-) (Although there is still some bureaucracy, and it's worth knowing what the standard requirements are.)
I'm not aware of any large pan-European broker, and I don't think this is an instance where being multi-national, as opposed to national (or even local), is of much advantage (either to you, or such an agent). I suppose a site like RightMove could be considered international as it has listings in Portugal, Spain, Bulgaria and so on. But it's really an advertising channel (for local brokers) rather than a broker itself. Racking my brain (it's old, so it takes a lot of racking), I did come up with ReMax, who are pretty international, maybe even global. But I think ReMax (and I suppose folks like Sotheby's International Realty) are probably serving quite affluent customers, and most likely focusing on much more upscale (= expensive) properties.
Usually, each country has some market-leading real estate brokers (mostly they are online ones, now). RightMove is big in the UK. BulgarianProperties has a lot of listings in Bulgaria. Idealista is big in Spain. ImmoScout/ImmoWelt are big in Germany. And so on. I would suggest you find these kinds of sites for the countries that you're most interested in. The web-based brokers are especially useful if you're still in Norway, as you can look at (virtually) many properties, so you can see what's on the market at what kind of price. I'm not exactly poor, but even a basic search would quickly show me that I can't afford to move to London, Barcelona, Munich, Marbella, or the Algarve. :-) Most listings have photos, but many of these agents also do a video, or have 3D room views, or even a live tour via Whatsapp or Viber.
The extras you mention (legal services, insurance) are not typically included in a "package". The standard model used by almost all brokers/agents is a commission for the sale/purchase of a property. However, of course, they will all have 3rd parties (law firms, insurance brokers) that they deal with regularly and can introduce you to. Similarly, they often can make introductions for those needing bank accounts or mortgage financing.
I recommend you use these websites and remote viewings to create a shortlist, rather than to make your final decision. Most of my colleagues here would, I think, recommend that you buy after viewing in person, rather than online. Accordingly, it might be worth picking a country (e.g. Portugal, Spain, Bulgaria) first, based on your key criteria (e.g. sunshine, house prices, taxation, etc.), and then using your freedom of movement to relocate for a few months (staying in one longer-term rental, or several short-term rentals in different places). This way you can explore several different locations, and view lots of properties.
I think you're considering Portugal and Bulgaria (and maybe more). Bulgaria is not high on the list of fancy destinations or retirement hotspots, but it has surprised me. It's a lovely (and relatively empty) country. It has cities and villages, mountains, lakes, and beaches. And it has low living costs, low taxation, and relatively low property prices. Whatever budget you have will go much further here.