I majored in Biology in college and had such a head start because I was already familiar with basic lab supplies, had used a microscope, and knew lab safety. Not every homeschooled student in my class had that same benefit. As a parent, it can be intimidating to think about acquiring lab supplies and taking on unfamiliar messes. I encourage you to find your curiosity and sense of adventure and travel the road of doing with me.
The good news is, doing science doesn't have to be expensive. Most of the materials I need for science this year are things I already have around or can make a point to save - half pint glass jars, shallow glass dishes, popsicle sticks, and moldy bread! For the more science specific items, I keep an eye out at thrift stores and local buy/sell/trade groups and snap up every inexpensive science kit that I see. For a few bucks, I've accumulated a bin of lenses, beakers, graduated cylinders, test tubes, magnets, small glass jars with lids, and other generic science items. I'm going to show you what I've gathered up from that bin and around the house, plus show you where and what I'd be buying if I had to start from scratch.
This is what I'v pulled out of my stash to use this year. The microscope kit is vintage and I picked it up at Goodwill for $25. Other than a few missing prepared slides, it is in perfect condition. If you can't wait to find a microscope in a thrift store, a similar kit is available for $70 from American Science Surplus. I also have a bag of miscellaneous hand lens, a box of prepared slides I made in college, and a stack of inexpensive plastic petri dishes. Assuming that you don't have a similar bin, head over to my favorite place to purchase science supplies, Home Science Tools! Follow this link to get $10 off your first order of $30 or more! (Disclaimer: I will also earn store credit if you use this referral link.) Their kits come with clear, easy to follow instructions and the website is clear about what is and is not included in each kit. If I were starting from scratch for this year, I'd purchase the Microscopic Life Kit and the Crayfish Dissection Kit. Their microscope selection is very professional but is overkill for a homeschool student who will use it for a year or two. That said, microscopes have great resale value in the homeschool community and a better microscope might be a good investment if you have multiple students that you plan to homeschool through middle and high school.
The entire rest of my science supply list comes out of basic household supplies or the grocery list
Tweezers
Medicine dropper
Spoon
Glass Jars
Cotton Balls
Spool of thread
Nut and bolt
Razor Blade
Food coloring
Onion
Bread
Unflavored Gelatin
Vegetable Stock
Tape
Plastic Wrap
The total lab supply cost should be about $120