I have tried everything to connect my electric guitar and have gotten nowhere. I've read all the walkthroughs on Cakewalk, tried Youtube, and asked a friend who has been using the program for years. I have my guitar connected to a Tascam US-2X2 (also having the same problem with the Scarlett 2i2) that is connected to my computer. I have tried every option on the interface and on the input drop down menu. My midi keyboard works fine and the interface works since I connect my headphones into it. I have Sonar Platinum and have been using it for a month so I'm still familiarizing myself with everything so please keep it Barney Style for me. Any help or suggestions is greatly appreciated. Thanks, guys.

You need to either
1) arm the track for record
2) select 'input echo' button
 
Without one of these you will not be able to monitor the track or see the level in the meters.
You also need to route the track's output to the Master bus and route the Master bus to your Tascam.
 
 

Wow, I honestly can't believe it was that simple. It is working, thank you very much. Didn't have the Echo turned on.

A related issue is "SONAR is suddenly really noisy." This happens when you have Input Echo turned on for inputs that have something plugged in, but you aren't using them and forgot that Input Echo was on. At least that's what I've heard...I would of course NEVER make a rookie mistake like that 
 
Another trick: Before recording a track, I always turn off the Global record button if it's on to make sure nothing is selected, then select the track on which I actually want to record.

Actually I never use input echo to record as my latency to high, and I would imagine a us 2x2 will be the same. Input echo has nothing to do with recording a track other than monitoring it.  You will here a digital delay of your guitar. Tascam interfaces have direct monitoring so you hear playback and the input directly in the phones or monitors. 
I was wondering if the OP had set the proper input source.