Ok, I blew out the fuel line between the tank and the filter. Could hear bubbling in the tank but no fuel. So I think it is somewhere between the tank and the filter.
Okay, you heard bubbles. That's good. Now you need to get the flow going. The L120 is not a gravity fed system. There is a feed tube in the tank about 1/4" above bottom that exits at the top with a 90° fitting . The fuel line is connected to it. This is now all filled with air. Suck on the end like you were trying to siphon gas. I use a vacuum squeeze-bulb but you can use any way you feel comfortable with, until you get a solid flow of fuel. Put a fuel line clamp on the hose and reconnect to the filter. Remove the clamp. You're ready to move forward.
If it were my L120, I'd have two options: choke on FULL, crank until it starts. Crank time is limited to 12-15 seconds with a 1 minute cooling period in between. May take up to a minute of cranking, maybe two before it fires.
Second option: (what I'd probably do!) Remove the air filter cover exposing the air horn inlet. Place 10 to 20 drops of fuel directly in the air horn. Crank and it should fire and run for a few seconds. Repeat until it runs solid. What you're doing is using the engine to run the fuel pump at operational speed to prime the system until you get fuel to the carb.
Now, I'm making a few assumptions here. You initially said you weren't getting fuel to the filter. I assume you have spark (no grounded mag wires, fuel solenoid clicking, and the air filter isn't blocked) and the fuel tank is full or nearly so. I assume it was running when you put it away last Fall.
What the second option does is eliminate your complete fuel delivery system in your troubleshooting. If it fires when you directly place fuel in the air horn, then the air and spark parts of the triad are working. That just leaves solenoid, pump, filter or defective tubing. Filter would be my next choice. They can look just fine, but have a "slime" buildup on the filter element that blocks all flow. Replace on a regular basis, not on looks. Do NOT expect to see it full of fuel. Some fuel with the rest fuel vapor is good enough.
You can check the pump next. Remove the outlet hose going to the carb and feplace with a length of tubing that you can place in a can. Crank and make sure your getting pulsed flow into the can. You may need to use a battery eliminator or jumper battery if you drain the internal battery too far. After a short period (fifteen seconds MAX) fuel should be flowing from a good pump.
If you're good up to here, the only two things left are defective solenoid or stuck float. You can do a quick check of the solenoid by listening for a click when you turn the key from OFF to ON. It's energized in any position except OFF. The click is the shutoff pin being pulled by the electromagnet allowing fuel to flow. If it clicks, it's probably good.
There is a small chance that you have an air leak (split, hole, loose clamp) in the fuel line near the tank outlet. Since you have to pull fuel from the tank with a slight vacuum, any air leak here will give you trouble.
That's about all I have.