Hi @gray! 
There are a lot of fun possibilities when it comes to making your own altar! I left a few resources and links about altar inspiration in your intro post (linking here so it’s easy to find), so I won’t duplicate them here, but I do just want to add the Beginner’s Spellcasting Tool guide as it has some info about basic tools and their purposes.
A note that not every practitioner needs all of the tools- one witch may enjoy candle spells while another prefers making spell jars or using incense. It’s all a matter of finding what works best for you.
As for clever ideas for using things you already have- I love the ideas Amethyst shared! There are some really great ones there. I second about using mugs or bowls as chalices, I have a whole assortment of dishware I like to use in spells. With a bit of creativity, thrift stores and rard sales are great places to find new tools for very cheap! 
Wishing you all the best as you set up your sacred space- blessed be!