No that sounds pretty ok IMO. But cories are shoaling fish and should be in groups of at least three with four or five being preferable. You also need to make sure your tank is cycled before adding corys because they are scaleless and can get burns from bad water quality very easily.
Try running your stock through AqAdvisor
.. it will give you a general sense of your stocking level. According to your specs your stocking level is about 83%... you always want to try to stay under 100% stocked IMO.
One more thing, tetras are known to be fin nippers so I would make sure you have alternate housing for the betta in case they decide to ruin his fins. Honestly I wouldn't put tetras in with a betta but I've heard that people do without issue so I guess is a case by case sort of thing.