At any fabric store either online or in brick and mortar you will find a mind boggling display of notions that can bewilder the novice sewer. Which are essential sewing notions, and which are a complete waste of money? As with most hobbies, you can spend an unending amount of money but it's best to start off with a small arsenal and build it up as you need it. Through the years I've made do with a very select part of my arsenal at temporary living situations and had unused items lay in drawers for years and years. I even have a gadget or two that I can't remember the purpose for. I definitely know the ones I can't live without. Let me give you my top 10 essential sewing notions:
1. Good sewing scissors. You don't have to have the nicest, most expensive pair to start (though these are nice indeed) but you should have a sharp pair with long enough blades to cut through lengths of fabric that are dedicated just to sewing. It doesn't take long to render them useless cutting paper, hair, and the other things they can get off to in a household. Have another pair for those odd things. Cutting out fabric with dull shears hurts your hands and tends to be inaccurate. If you intend to mostly quilt, you will quickly want a rotary cutter, some rulers and a self healing mat as well, but the sewing scissors come first.
2. An assortment of needles. The "universal" works well on woven fabrics, but if you try to sew on knits without a ball point you will have a home-made looking mess. Holes in your fabric and skipped stitches quickly make sewing less fun. Denim, leather, or heavy fabrics require special needles too. If you get a specialty thread, like a top stitch, rayon, or metallic thread you will need a needle for those, the needle package will tell you what it is used for.
3. A long tape measure. The more advanced your sewing projects become, the more you will use math skills. To make things fit (a body, a window, a front to a back) you need accurate measurements.
4. A brush for getting lint out of the needle and bobbin areas, a small screwdriver if required to get to the bobbin area, and some quality sewing machine oil (not WD-40 or other lubricants). Most of my machines have seldom or never needed anymore maintenance than these tools provide, but they need this maintenance often. Not doing it results in machine wear and skipped stitches, holes, and snarly messes.
5. Straight pins. It hasn't mattered to me much what kind, though they make specialty ones for different fabrics or sewing projects. Throw them away when they are bent, use them to keep layers together.
6. Safety Pins. Attach them to ribbon or elastic to draw through casings. They can be used to baste a quilt before sewing, but having done that once I now use a quilt basting spray adhesive that is expensive but worth it. Safety pins can keep groups of buttons together if you recycle or have them off cards.
7. The dreaded seam ripper. I hate having to use it, but I hate more needing it and not finding it. I have used a razor blade, I've even used a pin to pull out a stitch or two at a time and snip and pull, repeat. The seam ripper helps you tear out mistakes in stitching. It also cuts out button holes.
8. An iron. Again, they make fabulous ones for heavy steam designed primarily with sewests in mind, but a basic one will do and is essential. You have to press as you go to get nice results. You have to.
9. A fabric marker. You already have some. They make nice (and cheap) water soluble and air soluble markers and a bunch of other kinds. Lots of times a simple pencil will work, and one of my favorites is a nice dry bath soap sliver, white is best but colors work too. Sometimes you really need to draw where things are going to meet or get folded or whatever.
10. There is a product called a hump jumper. It is probably a fine thing, but I have always had a piece of folded light cardboard packaging lying under my sewing machine neck that I use the same way. When crossing a previous seam or part of a project that has more thickness than what you are sewing, like blue jean seams, the foot tilts up at an angle and the stitches get very tight. Sometimes the needle breaks, marring your machine plate as it does. If you leave the needle down and raise the foot up and slide the jumper or cardboard under the back at the height that you are approaching, it eliminates all those problems. How many needles did I break before I learned to always do this? 20? 40? Lots and lots.
These are my top ten tools. As you get more experience you'll find more and more that make your life easier for specific projects, and if I were giving you a specific project I would include more. These essentials will get you started without too much anguish, and will make your joy that much greater when you discover some of those others. Have fun!