Optimizing Blender on iMac 2017

Hello.

Can anyone help me with optimizing Blender?

I have 2017 iMac 5K (3,4 GHz Intel Core i5, Radeon Pro 570 4 GB, 40 GB 2400 MHz DDR4) and Blender is very slow on this.

I’m new to Blender and I’m not a technical user, so I need any tip on how to get better performance on my iMac. Any tips?

Thank you!