Hello! I hope you enjoy it here and welcome to Ribblr, to answer your question I suggest regular yarn (regular being anything but fluffy, chenille, eyelash, plush, novelty yarn, etc) perhaps weight 4 or bulkier so you can see your stitches easier as opposed to fluffy yarn where you have to feel your stitches rather than see which can be much more difficult to count stitches and ensure correct stitch count depending on the pattern
Here’s something I try to do when I can for newcomers 
if you ever need help never hesitate to ask in the community, if you need immediate answers feel free to use the help center, search in the community, or the wiki [link below] testing guidelines and community guidelines if needed Happy crafting! Hope to see your crafts soon as well congrats on your first post