Free Resources:

Blueletterbible.org- This is an amazing free online resource that is extremely helpful for gaining a better knowledge of the original languages the Bible was written in. You can look up any passage and it will give you an interlinear from which you can click on any Greek or Hebrew word to learn more. You can learn the different definitions of each word, how it’s used in context, cross references for how many times each word is used in the Bible, on and on. 

netbible.org- This is the website for the New English Translation of The Bible (NET). It is a unique and incredible study Bible that contains 60,000 study notes regarding translation decisions and textual issues. You can buy a physical copy or use it online for free! They’ve made it available not only on their website, but other popular Bible apps as well (such as YouVersion and BibleGateway). 

studylight.org- Another great website that has a good amount of public domain commentaries for free. You can find commentaries from the likes of Matthew Henry, Albert Barnes, Matthew Pool, John Calvin, John Wesley, and many more. There are Bible reading plans and even historical writings there (such as various creeds and confessions from church history). 

General Bible Study:

ESV Study Bible - An amazing general study resource that I would recommend to everyone. It's loaded with great scholarship and there are over 40 well written articles ranging from Biblical ethics to textual criticism and everything in between. I find the introductions to each book of the Bible extremely helpful for general study or even in teaching prep. It's just enough information without being exhaustive. https://amzn.to/499BViH

Matthew Henry’s Commentary on the Whole Bible- There is a reason this has been such a beloved commentary for hundreds of years. The expositional insights of a later Puritan are always beautiful and deep. Matthew Henry is very quotable and overall is very edifying for the soul. Modern commentaries do a good job of getting knowledge in the head, Henry does a good job of connecting with the heart! You can find it online for free (see studylight.org above) or buy physical copies. https://amzn.to/4qvWqxs

New Bible Commentary- This single volume commentary on the whole Bible along with a solid study Bible would make a great 1-2 punch for the average layman in terms of general Bible study. Maybe add to that the Matthew Henry Commentary for a good Puritan perspective and that would be the trifecta. That said, this commentary is very solid for a whole Bible commentary and I even find it useful despite having multiple single volume commentaries for each book of the Bible. https://amzn.to/4qLB8fp