Simple soil, fertilizer question.

Hello :) just wondering if anyone would like to reccomend some soil and fertilizer. I just had my first succesful seed to bud plant. I have a strong light so thats all good. The soil i used was used before ( i know i was lazy ) and i didnt use any fertilizer. Is the more natural way with no fertilizer? because i was happy with the bud i got(goood seed) so maybe just what's a good soil? I was thinking organic miracle grow and maybe some fish emulsion 3-2-2. obviously im just looking for the cheapest way. So yeah any reccomendations would be appreciated. Also for a small growing space (half a closet) whats the best size pot to fit the most number of plants. Maybe the 6in. pots? are those alright? 1love