I think my favourite TAL pattern has to be the cap sleeve dress. It’s just exactly my style and I know I’m going to make many, many different versions of it in different fabrics. It was actually one of the patterns that convinced me I needed to get a sewing machine.
Start playing around before taking on an actual garment. Figure out how your machine works and try various seams on fabric scraps. Use different materials, to get a feeling for how they “act” under a presser foot. Learning takes doing.