welcome, Buggy
I like to 'pop' lots of seed and pick the best to grow. Of course when I buy seed from the vendors I really can't afford that, only with 'free' seeds.
You can grow 16 or more plants in a square meter space or you can just grow a half dozen. This depends on the pot size and how long you're going to veg them. Basically, you'll want to fill the footprint with pots. I use 3 gallon bags for sea of green and 5 gallon pails for larger plants. You can use larger or smaller.
A 10 foot x 2.5 foot space will require a lot of lighting and ventilation. Use reflective panels or tent to corral the light.

Check out some grow logs that feature similar methods to yours. here's one of my recent grows. And another

Good luck~