Step 2: Add Visual Effect to the Stroke.Select the color you want for the stroke and choose from the variety of stroke size options in the panel that you preferred.
When you open your document, open the Appearance Panel to use adjust the thickness or weight of the stroke. Below are simple steps that you can follow if you need to change the thickness or weight of the stroke in Adobe Illustrator. There are many tools and options that you can easily use to modify the thickness or size of the stroke in your artwork or illustration. How to Change Stroke Thickness in Adobe Illustrator