I'm thinking of buying entry level DSLR Nikon D3500. I haven't used DSLR before, so I'm not sure if it is a good decision to buy DSLR. I would like to know if with this camera I can shoot portraits with blured background such as on the new smartphones with two cameras. Another thing I want to know if buying DSLR is good for beginners in photography and amateur photographers and is it worth the money.

I'm new in this community, so I'm not sure if this is the right place to ask this question.
['https://photo.stackexchange.com/questions/108713', 'https://photo.stackexchange.com', 'https://photo.stackexchange.com/users/85164/']
**It's not the camera, it's the lens.**

If you want a cheap and good option for shooting portrait pictures, you should definitely purchase in addition to a DSLR, a 50mm f/1.8 "nifty fifty" lens. Do expect to spend $100-$200 for the lens.

50mm is about optimal for portraits, because the relatively long 50mm focal length on crop sensor cameras is long enough to obtain blurred background while being short enough that the distance to the subject need not be excessive.

At 50mm, the kit zoom probably has f/5.6 aperture. A nifty fifty has f/1.8 aperture, which is more than 3x the difference. Three times the background blur with a nifty fifty.

Even an expensive (and heavy and large!) zoom (17-55mm f/2.8, $700-$1000) cannot match a nifty fifty (50mm f/1.8, $100-$200).

Also, the f/1.8 aperture is useful in low light no flash situations: the f/1.8 collects 9.68x the amount of light than the f/5.6 (@50mm) zoom.
A DX sensor has a crop factor of 2/3. You are presumably talking about the 18-55mm kit lens. For portrait work, you'd likely use it at its long end, giving you about 83mm equivalent focal length with an aperture of 1:5.6. That will give you the same depth of field as an 1:8 aperture setting on a 35mm film camera with the same kind of effective focal length which is quite discernible but not terribly strong. You'll want to arrange your scene appropriately so that the background is indeed some distance away.

The computational blurring on a smartphone aims to emulate the visuals of quite smaller depth of field, namely larger sensors/aperture. If your viewing device ends up being a smartphone, you'll not likely be able to appreciate the much more natural action of optical object isolation (but due to camera and lens parameters, more subtle) over computational approaches, particularly since the small display scale increases the perceived depth of field.

If you are going for print, things will look different already, however.

Is it worth the money? It depends on your purpose. If you don't intend to throw further money at the problem of doing portraits (namely buying a suitable prime lens or a less basic zoom lens), you'd likely be better off with a 15-year old Sony DSC-R1. It has about the same sensor size, goes to 120mm equivalent at 1:4.8 aperture. Its age has definite implications for handling (no image stabilisation, so tripod wanted), speed, storage media, convenience, autofocus, sensor resolution (10MP) and sensitivity (ISO400 is where noise starts) and so on. But for your principal criterion of a small depth of field at reasonable image quality in portrait situations, it will deliver more than the D3500 with a kit lens, but you will be left without an upgrade path.

Of course, analog cameras will deliver effortlessly in that category at quite cheaper secondhand prices but handling film is a hassle in comparison. Even if you do want to end up using film, learning your photographic skills using digital first is going to save you a lot of time and money.

To summarize: you want to throw money at a problem. The direction you are planning to throw it in is a good starting point but you'll need to throw more in that direction before achieving your goals. Partial goals may be achieved cheaper by throwing in a different direction first and thus getting a good idea how and where to throw larger wads of money for best effect at some later point of time.

Buying your learning gear preowned often means that as you develop a good idea where you want to be heading for real, the gear retains most of its resale value. Newer gear often is more supportive with regard to getting good results with moderate effort, however.