The 3sc means "three single crochets." When the pattern says "in chain," it means you are to perform the stitch(is) in the actual chain stitch of the row below as opposed to in the space created by the chain stitch (which would be called a "chain space.").
No. The last chain is the one before that one.
The cc crochet abbreviation stands for "chain stitch." It is used in crocheting to create a foundation chain for the project. The chain stitch is the most basic stitch in crochet and is often used as the starting point for many patterns.
Yarn Over.
Slip Stitch
Foundation chain. This is the first group of chains that you make at the start of a project.
Probably "spaces". As in skip spaces.
How am I supposed to know I’m asking the question here
yrn is the abbreviation for 'yarn' - the material you are knitting or crocheting with
Usually, rem would mean "remaining", as in, "for all remaining stitches" etc.
My grandmother loves crocheting.
It means decrease, usually by crocheting stitches together.
If you mean do you have to purchase a crochet hook, no you don't. You can make your own. You CAN make a chain without a crochet hook, just using your fingers (just did it myself). Working into the chain without a tool would be more difficult, and would probably be more frustrating than fun.