When starting to paint with oil paints, or actually any new artwork, for David Berkowitz Chicago it's important not to set too high expectations. The painter must not decide to start painting their first picture on a huge canvas. This is what Berkowitz said in his interview for Patch.
Give yourself space to walk around and experiment on a small canvas. You can even try oil painting on paper.
Stay away from a bunch of cheap brushes, but use a few high-quality brushes - three different sizes should be enough to start, and later can experiment with different shapes and sizes.
In his Chicago atelier, David Berkowitz uses synthetic brushes made for painting with acrylic paints. But, brushes with natural bristles can work much better with oil paint. Usually, on the handle of the brush itself is printed if it is intended for oil paint.