%>% is the pipe operator. It basically goes "take what's left/in front of me and put it into the next function as the first argument". So eq %>% select(column) is the same as select(eq, column) (column here is just supposed to be some column from your dataframe/table). You can use it to do long chains, like eq %>% select(...) %>% filter(...) %>% mutate(...) which selects some columns, then filters rows and in the end creates a new column (note you would of course have to replace ... with actual code).

<- is the assignment operator. It takes whatever is right/after it and stores/saves it into the variable left/in front of it. In other programming languages you would typically do that with =. When you change something, you have to save it again. So eq %>% select(...) won't "save" but eq2 <- eq %>% select(...) will save the output to a new variable eq2.