There are a few reasons you could be getting foam, but the most common is line length and line width. The width should be 3/16th ID (im sure if it came with your tower then its the proper width). Also for line length i think 6 to 7 ft is good. Line is pretty cheap so i would replace it if its easy for you to do.
Keep in mind that usually your first pour will be foamy since the beer warms up a lot coming up to the tower. The second pour usually isnt as foamy. Finally, its possible you overcarbed your beer. Dont know what strategy you used, but if you forced carbed it may be over carbed and you might wanna bleed pressure.
Sorry if I'm telling you things you already know. Just wanna be thorough.