<p>I'm new to 3D Printing. I've created this star from Blender3d. As far as I know, most printers require a flat bottom.</p>

<p>As you can see (blue line is Z-axis, red line is X-axis, green line Y-axis), the star doesn't have any flat sides or points.</p>

<p><a href="https://i.stack.imgur.com/Mh6Bw.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Mh6Bw.png" alt="enter image description here"></a></p>

<p>There's a hole in the middle of the star.
<a href="https://i.stack.imgur.com/V4a6C.png" rel="noreferrer"><img src="https://i.stack.imgur.com/V4a6C.png" alt="enter image description here"></a></p>

<p>Is there a printer (brand/model) that can print this object that doesn't have any flat bottom or sides having a hole that goes through in the middle? Any workarounds to print this object?</p>

Typical FDM desktop 3D printers might struggle with this model as it requires you to either print large overhangs and use support structure (when printed laying down), or lacks a natural flat bottom surface to get good print adhesion (when printed upright). A couple of suggestions:
Some FDM printers are great at printing support, and some even allow you to print dissolvable support structure. If you find one of these, you are home safe.
You could split the model in two, print those parts separately, and then glue them together afterwards. This is quite common for complex models, and allows you to print your model on even basic FDM printers. Tom's answer illustrates this well.
There are naturally other 3D printer technologies too (SLA, resin etc.), but I have no practical experience with these myself, and leave it up to others to give you a good answer regarding these.