Help! Latent change score modelling

A reviewer has asked myself and my co-author to conduct some additional analysis using latent change score modelling for a computational cognitive modelling paper we have submitted. As I have absolutely no idea how to conduct any form of structural equation modelling, I am asking the universe (i.e., you!) for help. If you can help, please do reach out. I am conducting all analysis in R, so will be looking to use the (seemingly excellent) lavaan package.

Power Table for Correlation

Final Year Psychology students across the UK are busy preparing their experimental work. Many students will be conducting correlation studies. Several of my own students are using correlation methods to explore the relationship between aspects of cognition and severity of certain clinical disorders (for example depression). A typical question I receive from students is “How many participants do I need for my study?” For my students I have developed a “Power Table for Correlations” to help them answer this question.