It really depends on your definition of “fit”, for some people it’s being thinner, for others it’s being stronger…
And it’s relative to your current position. If you’re obese, you may consider doing the 7 minute workout challenge once a day every day, and you’ll get fit over time.
For others with better baseline fitness, this isn’t likely to make much difference, and indeed diet will make a greater overall impact on your health.
Generally speaking, you can get fit with very little equipment at all, you can build your strength with weights (cheap on amazon), or with a pull up bar. Go for runs when you can to build cardio and improve your vascular health.
I think there’s a lot of dogma attached to spending upwards of £100 a month on gym memberships, when all you need is motivation and willingness to get outside more.