Look at flavour profiles - some are fruity, some are candy, some are lemony some are spicey etc
Also, are there any 'medical benefits' you maybe looking for.
Time can be a factor, e.g amnesia is a 12+ week flower period, others can be done in 7.
Additionally, photoperiod or autoflower, both have their place with pros & cons.
3x3 is enough for 2 medium plants (with side light for a baby or two).
The NL is a classic and comes as photo & auto
Hope this illuminates the road ahead a little.
GL