DO NOT GET GOLDFISH!!!!!they have very different water needs than a betta,either way,if you make it comfortable for you goldy your betta will suffer and vise versa,plus a ten gal is way to small for a goldfish.
these are good stocking plans IMO,
1 betta (male or female)
6 neon tetras
5 ghost shrimp
1 betta
4 cory cats
one snail
1 betta
6 black neon tetras
5 ghost shrimp
1 betta
1 dwarf gourami(be ready to seperate,i have kept them together before but you never know...)
3 cory cats
2 bettas (divided if course)
planted with ghost shrimp on both sides and maby a mystery snail on both sides also.