It's mainly a problem of supply and usage.
To travel at light speed, you need an infinite amount of fuel.
With warp speed, you still go about as fast, and it uses less fuel.
Food isn't unlimited ever though, that's a big problem.
We'd have to send enough food to last for the entire trip, then every day or every week or every month or something send enough food to last that amount of time, a big usage of money and also fuel.
You have to have enough fuel to get enough force to break through the atmosphere as well as the gravitational pull of Earth, we can do that today, but we use up too much of our fuel doing it.
We would need to seriously do some thinking and research before space travel is possible to the extent that we can actually inhabit other planets/moons.
Mars, for instance, would need to be terraformed to have Earth-like atmospheric properties, not an inexpensive task.