How to begin

This is definitely something that comes with experience, but pulling your yarn too tight will make it impossible to put your hook in any stitches. Likewise, having your stitches too loose can make it easier to see, but makes it messy and can cause uneveness and make the piece floppy. I would recommend leaning more into too loose to start with. A good way to feel your tension is to wrap your yarn around your fingers. I personally wrap it over my index finger and let the yarn rest under my pinky. Others wrap it in a loop around fingers (e.g index & pink), but my skin gets too irritated if I go too fast or it gets caught. Try a few ways and do what's best for you!

There are a few layers to this so I am going to break it down into sections. First, what are the different types of stitches. I am going to use US crochet terminology as it's more common in my experience. The first stitches you should learn are called chains, slip stitches, single crochets and double crochets. Understanding the concepts used to make those stiches should provide a solid foundation. Secondly, what is the structure of a stitch? There is two parts of the finished stitch. These are called the front loop (FLO) and back loop (BLO). {The abbreviations indicate that you are only supposed to go through that respective loop.} For a visual of the loop, see the photo credited by Yarnspritations. While on the hook, there is three parts of a single crochet, which is the best example as it is one of the most used stitches. The loop furthest away from the hook is the top loop, which will make up the top half of the stitch. The loop in the middle will be the bottom half of the stitch. The loop on the hook that is taken through the previous two hoops will make up the top half of the next stitch. (This is important as if you pull through with a different colour, you can do colour transitions.) For a visual of this concept, see the image credited by Annie's Catalog.

Please just do it! When doing smaller pieces, it may be easier to keep track but getting into the habit of marking the first stitch in a row will be a lifesaver when making amigurumi. It is so easy to loose count and knowing where you are up to based off the marker is much better than re-counting the entire project.I personally use stitch markers as they don't fall out, but if im marking multiple, I use a different coloured yarn (Like the hedgehog as I need to mark which rows I put texture on). Amazon can provide a ton for $5 so even if you loose some (or all of them like me), you can have two others to fall back on. Some beginner kits also come with stitch markers. 

For beginners learning, I would reccommend starting with a basic sheet of crochet. It doesn't have to be a big project, a simple small square should suffice. (Check out youtube for a 'Absolute beginner tutorial', as they are more detailed than a basic tutorial.). Once you feel confident, advancing to amigurumi starts with a ball. I used this tutorial by Knit Grit, but feel free to search youtube for another if it doesn't work for you. Once you got those basics down, A good first (actuall) project is a whale! (Link for tutorial, suprisingly also by Knit Grit...? I guess I just liked their tutorials ¯\_(ツ)_/¯ ) I can confidently say that this was my first project, and it does have a left handed tutorial (in the description) for the lefties!