How good is a BMW for a first car?
The thing with BMWs, Audis, Volkswagens and Mercedes is there is the purchase price and then massive costs to keep them on the road. They cost a lot to keep on the road and they cost a lot to fix if anything goes wrong with them. This combined with the fact that BMWs, Audis, Volkswagens and Mercedes have been named the most unreliable cars in the world in a 2012 study. Here is an example try $300 for a tiny hose. Then there is also the fact that parts often have to spend weeks getting here from Germany.
I know people with these sorts of cars and they have all had trouble. Two of the BMW owners have hand endless trouble.
So to answer your question while a BMW might be a nice car to drive be prepared for it to burn up your bank account really badly.
Not unless you have a boatload of money for upkeep and maintenance. Almost anything for a BMW, from a spark plug to a dust cover on your front axle is going to cost more than any similar part for an American or Japanese car.
If you're going to buy used, you could do worse than some low-mileage Nissan or Toyota, and your gas costs and upkeep will almost certainly be less. I have an older Nissan truck right now, partially restored. Last month I bought a complete set of tie-rod ends for the steering assembly. Pretty easy to install, too. The cost for both the drivers' and passenger side set cost me less than a hundred dollars.
The cost for those same parts on a lower-end BMW 228 are over $200, but where they REALLY get you on BMW's is for the LABOR. Labor costs on BMW's and other high-end European vehicles can go sky-high.
So unless you have deep pockets, are an excellent mechanic, or don't mind maxing out your credit card at the repair shop, you could do better for a first car than a BMW. My first rig was a 1972 Datsun truck. You could switch out the engine cheap in less than two hours.
Depends on the specific Beemer in question, but generally I'd say yes, they are well-made and safe.
A clapped-out el Cheapo Beemermobile though will be a lot more beat up than a less prestigious brand for the same price of course, and possibly have been "customised" but some idiot prole hack who doesn't know what he's doing.
Also probably best stay away from M3/M5 as a beginner for some time until you know what you're doing when you're driving it.
First or last, BMW is one of the best vehicles in my experience. I got rear ended in my 328I years ago at 60 mph and walked away after being sandwiched into the car in front of me. The girl was putting on make up and I saw it coming so braced myself the best I could, my rear wheels were in her windshield as her car dove under my rear bumper. For those who don't know, the spare tire is used as part of the rear protection system, so it took up much of the impact and stopped a total rear end intrusion. I was already a several BMW owner, as well as a few Mercedes, Audi and Jaguars in between, but ever since accident, I have had nothing but BMW's.
I believe every car can be a good first car. It all depends on how much money you are willing to spend on that first car.
Also, take into account the status value a BMW might have. This might not be important to you, however some people will envy you when you show up in your brand new BMW.
If you can afford it, just buy it and enjoy it.
Most -if not all- BMW's are very well made and easy and fun to drive. So as for the first car aspect... you will not have any problems driving it. Unless of course you choose to buy an M3 or M4. I believe they might be to powerful for a beginning driver.
Here is the thing. BMWs are nice cars. They are good driving cars. They are expensive. Maintenance is expensive. They are not good values for the money.
If you can comfortably afford the car and the maintenance, then sure, get a BMW if that's what you want. But if the car is a stretch, if you find yourself worrying if you can afford it or not, or you're leasing because you can afford that lease payment but can't afford to buy it, maybe you should get something cheaper. There are perfectly good cars that cost a lot less.