Here are some guides I made for my students to help them remember how to use the TI-84 Plus CE (though I think it’s pretty much the same for all TI-84s) to calculate statistics and create graphs for univariate and bivariate data. They’re designed for interactive notebooks, but I’m sure they’d still be useful for teachers who don’t use INBs.
1-Var Page 1: Entering Data and Calculating Statistics 
1-Var Page 2: Histograms 
1-Var Page 3: Boxplots
2-Var Page 1: Entering Data and Calculating
2-Var Page 2: Scatterplots
2-Var Page 3: Regression
THANKS!