I store my food in glass jars and reusable containers (most of which are plastic, but no blog is perfect; small steps are better than none). You can go out and buy some mason jars, but if you kept track of how many jars you buy products in, you’d be surprised. Within the span of two or three months, you can have your own bonafide jar collection. Take a look at your jars of pickles, dips, olives, pasta sauce- they don’t just have to be mason jars. They’re easy to wash, and you can actually convert one into a water bottle if you protect it from breakage (a friend of mine used cloth and rubber bands). You can also save any plastic wrap and foil you use. If they’re clean (and you can clean them), you can reuse them. I personally cook grains and beans (and in this case vegan mayo) and store it all in jars in the fridge for later use.
Jars are also good for carrying lunch. While you can put most glass in the microwave, it heats up quickly, so be careful (and remember to remove the lid!). You can get creative and have cute little lunches like this.