So you've got one pyramid right There are probably different ways to print different pyramids one next to another. You can reuse some of the logic that you've already done.
Let's say you have three pyramids : 3, 2, 4
1. Find out which is the highest (highest=4)
2. Loop highest times ("row" = highest to 0 excluded)
2.1 Loop through each pyramids ("pyramidno" = 0 to 3 excluded)
2.1.1 Print the stars for the current "row" of the current pyramid (you need to know the max width of the current pyramid). If the current "row" is above the highest row of the current pyramid, print only spaces.
Try to build your program according to this algorithm, bits by bits. Start by making a method which returns the highest number of rows (step 1). etc...