The abbreviations won't bother you for long. It's all just shorthand for knit this many, purl this many, and occasionally do something else that sounds weird but won't be after you try it. If you like, you can look up the abbreviations on your patterns before you start and write them out so you'll be confident. We've all been where you are, and even now, some pattern designers aren't too clear about what they take for granted...and then there are typos. Hoo boy, re there typos! When you get stuck or even just concerned, we'll all help.
One of the best things you can do for yourself is to learn to recognize what a knit stitch looks like and what a purl looks like. Also, realize that the back of a knit is a purl and the back of a purl is a knit. You're still just pulling one loop of yarn through another.
How you join projects that are made in pieces can be a whole subject in itself, but usually it's best to use yarn instead of thread. In case you're wondering...yes, I did that once too. At least that was easy to fix when the knitted afghan pieces stretched and popped the thread. Hey, the pattern just said "sew together" and didn't say how!