Take the drama out of it
After a pattern is chosen turn over the envelope and read the fabric suggestions. This is where you will start the search for fabric. Decide when you will wear the garment: to the gym, to the father-daughter dance, family function, school. Then go to the isle with that type of fabric. Trust your judgement. When the fabric is found unroll it and toss it up in your hands. Notice how it falls back into your hands. That is called the hand of the fabric. Your are watching how it will behave as a garment. Or for a project. Next, hold it up to you to find out if you like the color. Maybe, look in the mirror.
If the pattern requires a knit measure your fabric against the gauge on the pattern.
All knit patterns will have a gauge.
Each pattern has a fabric chart to inform how much to purchase.
Move your finger down the left side of the chart to the "view" you are making then move it across according to the width of the fabric (45" or 60") to line up with the correct size being made. If the fabric has nap (a person, velvet, words) then purchase more.