I have a Blackstar ID:Core 20 but i dont like its distortion. Im thinking of buying a distortion pedal (Boss DS-1) but i heard that modeling amps dont take pedals well. can anyone help me out with this? will the ID:Core 20 work well with a distortion pedal
Whoever told you that modeling amps don't take pedals well was right. They generally do not. Especially drive pedals, it does not work the same as it would in front of a proper tube amp.

I suggest to save your money and work with your amp some more.
The ID Cores are just like that... the distortion sounds very plasticky and fake. It's ok with light gain, but when you start cranking the gain a bit more, it starts sounding like ass.

Either play with less distortion or play with the EQ settings a bit. You probably already know this, but you can have access to a 3-band EQ if you use the Insider software.

Save your money and buy a better amp when you feel the need for it.