In my opinion starting out with ADA aquasoil as your first substrate is not the best idea. To use that substrate successfully you have to be willing to do extra water changes for a few weeks to control the ammonia it leaches into the water. Of course it can be done, but with all of the other things you will be trying to learn and get used to, why complicate things.
If you use 3M color quartz black as a substrate you will have an inert substrate, which means you will be relying on fertilizing the water for the plants to grow. That is a good way to learn fertilizing.
Or, you could use
AquariumPlants.com's own: Freshwater Plant Substrate, which is a dark gray material with a high cation exchange capacity (CEC), which helps make fertilizers available to plant roots. It is pretty cheap too.
For lighting a 25 gallon tank, it depends on the length of the tank. If it is a 24 inch long tank or a 30 inch long tank or something else, that limits the length of bulbs you can use. Whatever you use should be about 55 watts or so, if it is PC bulbs, or perhaps 40 watts or so of T5 bulbs, with reflectors in both case. That would let you grow almost any plant you would want, but wouldn't be so bright that avoiding algae would be difficult.