So much depends on what you want to knit. If you just like one or two particular things, then you won’t need so many needles and such. I know, for myself, when I started, I’d read a pattern and it would call for a certain size needle, so I went out to buy that size. Next project called for a different size. After buying quite a few different sizes, and realizing this was going to add up, I discovered the Knitpicks Options set…I went ahead and bought that set because it was much cheaper than buying all the individual sizes.
So, if you’re only going to knit mostly on a couple different sizes, just get those and don’t worry about it. But if you think you’ll need a number of different sizes, an interchangeable set is well worth the money.
A little thing of stitch markers, a needle gauge, some tapestry needles for weaving in ends, are all nice to have. I bought a bunch of point protectors, but found with the circular needles, I don’t need them as much as with the straights. Most of the little gadgets, I’d just pick up as you need them.
Welcome to knitting! It’s a great addiction.