Hmm, im not a pro grower, but not quite a novice either... my opinion is " why not try it out"
maybe you might get a smaller yield than if you planted in say may or april... but then again I'm not sure where you live... where I am if i planted in april there would have still been 2 feet of snow on the ground.
These are free seeds my friend so go ahead and have some fun with them, you can always get new ones next year
either you can buy "grow bags" which are convenient, available in different sizes such as 5gallon, already with drain holes, and easy to move around if needed OR>>>
you can dig some holes in the ground. If you use grow bags its easier to move around and a lot less labour, but if you use holes in the ground (3 feet by 3feet) then you can go on a vacation without
worrying that your plants have dried out in the summer, as they will not need as much water being insulated by the ground.
so either way, get some good quality soil (none of this chemical fertilizer garbage soil such as miracle grow), just go with some organic stuff, black earth or foxfarm soil, mix in some perlite, maybe some cow pooh or guano or make it easier by buying the fertilizer in liquid form (google: fox farm organics) and then just follow the reccomended feeding schedule ...
definately start the plant indoors until it has maybe 3 or 4 sets of leaves, then very carefully transplant it into the hole you dug or the grow bag that you filled with mixed soil (perlite, soil or whatever medium you use, and a bit of nutrients)
then voila... now you play the waiting game..
then you have to think about pests... bugs, rodents, neighbours... you can put some chicken wire around them for rodents, spray the leaves with pyrethrum based insecticide (plant based... more safe... dont use chemical crap) lightly if you start getting insect pests, and for neighbours you should find some way of blending these plants in covertly (even if its legal) because people get jealous, and greedy..
let me know if you have any more questions... welcome to the great outdoors!