You'll want to learn about "duration", which represents a bond's response to rising yields. While it's an oversimplification compared to a yield curve, it's a very helpful way of considering all the fund's bonds with just one number.
According to Vanguard's website, VTEB (Municipal Bond ETF) has a 30-day SEC yield of 2.56% with a duration of 5.6 years. Let's assume all bond yields move in sync, and say they just rose 0.25%. That means VTEB's bonds are old news, with a yield worse than new bonds. So VTEB takes an impact equal to: 0.25% x -1 x 5.6 = 1.9%. VTEB should lose -1.9% when yields rise by 0.25%. If yields fall (-0.25%) it should gain 1.9% in value. That's why duration is a useful simplification (in practice 2-year bonds and 30-year bonds do not necessarily move the same amount).
There's also the quality of the bonds, ranging from AAA to AA for high quality, A or BBB for corporate bonds, and then below that for junk bonds (or "high yield" or "below investment grade"). If you see a higher yield "for free", the bond market is too efficient for that - you're probably taking on additional risk.
Note muni bonds should be that significant in your portfolio until you approach retirement. So more important than understanding bonds is checking if your bond allocation is appropriate for your expected retirement. You can peek at Vanguard's target date funds to see if you're allocating too much or too little to bonds.