Smaller plant in the back looks like it may have a tendency to become puny. Notice how wide the main stem is between nodes (sets of leaves)? I would prefer the plant to be bushier than it looks now and now is the time to "fix" it.
Two best suggestions are FIM'ing or topping. I would go with topping as a beginner. Find the top crown. Should be dime-sized or so and shaped like a cursive capital V. Remove that whole V assembly directly underneath that shape with a small set of disinfected scissors. Try to make a clean cut parallel to the floor. You should be removing no more than inch or so in height. Topping causes the plant to stay shorter and add more side-branching, bushier.
Good luck, BigSteve.