
If you are a beginner at sewing and have around 2 months of sewing non-stretch fabrics but are afraid of handling knits, here is what you can do like me.
BlankSlatePatterns provides a beginner pattern here: https://blankslatepatterns.com/collections/women/products/blanc-t-shirt
You can download for free if you join their Facebook group at https://www.facebook.com/groups/BlankSlatePatterns
Melissa gives very easy to follow instructions and the group is very helpful where you can ask your questions.
Below are my T-shirts.

Organic medium weight rib knit fabric.
Ball point needle.
Stretch Stitch
Bias tape on the neck line.

Organic light weight rib knit fabric.
twin stretch needle, adjusted bobbin tension(1 whole turn anti clock wise) and 5.5 upper thread tension (always test stitch for your fabric scrap, it must form a zig zag on the wrong side with the bobbin thread).
No bias tape on the neck line.
Learn more about twin needles here: https://oliverands.com/community/blog/2016/02/tips-and-tricks-for-twin-needle-hemming.html
Learn more about thread tension here: http://www.threadsmagazine.com/item/4302/understanding-thread-tension/page/all