Hello Brittany, 

Thanks for reaching out to UVM Extension Master Gardener Helpline. 

Sorry to hear about the insect pressure on your delicate seedlings. I consulted with some colleagues and from the photos it looks like the first photo on your basil could be flea beetle (small irregular holes), but it could be a combination of slugs or other beetles. It looks like they are  

Have you been able to see any of the culprits in action? Your best bet in identifying and mitigating is to catch them in the act.  Or better yet, consider using row covers at planting time. 

The second photo is likely cucumber beetles. The third photo is hard to tell, but the damage looks minor currently. 

I've listed a few extra resources below. Hope that helps! Happy gardening! 

Further Resources: 

https://extension.umn.edu/yard-and-garden-insects/flea-beetles

https://extension.umn.edu/yard-and-garden-insects/cucumber-beetles

https://extension.umd.edu/resource/row-covers/