Clutch has no resistance, feels broken?

Very strange, I started up my 07 Honda Fit and noticed out of nowhere the clutch had a hard time shifting gears… The car's clutch previous to that had actually been stronger than most cars I've ridden in. Then, after not driving it for some time after that, I get in and start it up again… But the clutch falls flat onto the floor almost like the pedal is broken or something, completely unable to put it into gear. My main two questions are, what could be wrong and approx what would it cost a 'backyard mechanic' to fix each possibility?

Studies show that drivers who are totally ignorant and lazy about basic maintenance are 700% more likely to experience expensive repairs than a driver who has a clue about the most basic mechanical functions and service procedures of the vehicle they drive. I suggest that to avoid future expense and unhappiness that you start educating yourself.

Question: Did you check the fluid level in the clutch fluid reservoir? Have you ever checked it, or any other fluid level than oil, if that? First rule of maintenance on older vehicles - check ALL fluid levels regularly. Chances are high that you could have avoided the present problem if you did. A leaky clutch master or slave cylinder will eventually deplete the fluid, and with a slow leak it will work ok right up to the point there isn't enough fluid in the system.

Check the clutch fluid level now. If the reservoir is low or empty, then the system has a leak. You might be able to partially restore clutch operation by filling the reservoir then very slowly pumping the pedal a number of times. With luck you can restore enough pressure for it to work, but you'll need to keep adding fluid until you fix it. If this suggestion fails, then next you'll need to try bleeding air from the system, something that you can do but it requires some knowledge and skill to do right, and it requires help from a 2nd person if you don't have a pressurized fluid can to feed fluid into the system while you open and close the check valve(s).

If filling the reservoir and bleeding the clutch hydraulic system doesn't fix the problem at least temporarily then either the clutch master cylinder or slave cylinder has failed and needs to be replaced. That is also something you could learn to do but the learning curve is a little steep and you may not have appropriate tools or an adequate place to work. Paying to have it fixed will probably be much quicker and not as frustrating as trying to tackle a job you're completely unfamiliar with and unprepared for.

I don't know

If it is a hydraulic fault shouldn't be too bad to do back yard, if it is actual clutch fault better off probably taking it to a mechanic (cos that will be gearbox out)

Get a proper mechanic to have a look.

That is classic for a failed clutch master or slave cylinder. You can wipe with a paper towel the firewall under the dash where the pushrod from the clutch pedal goes through. If it is wet with a clear oily liquid the master cylinder is bad. A failed slave cylinder is harder to look at but quick for a mechanic.

Expect to pay about $200 parts and labor for either.

That's exactly what happens when the clutch hydraulic system has a leak and air gets into the system. The most common reason is a leaking slave cylinder. It's a cheap repair to do your self. Advance Auto has the slave cylinder. You'll need a bottle of DOT 3 brake fluid to put into the clutch master cylinder reservoir. When you bleed the system you need two people. One to work the bleeder screw on the slave cylinder and the other person to work the clutch pedal with their hand. You don't pump the clutch pedal as you would when doing brake bleeding. You need to just hold the pedal down while the other person quickly opens and closes the slave cylinder bleeder screw. It take a good dozen repetitions and you need to top up the reservoir every three times. The bleeder screw has to be cracked and closed fast!