I wouldn't put Danios in a tank that small. They need big swimming room and will look sad in a smaller tank. The white clouds are doable, a 10 gallon would be better but make sure to keep the temp low as they are coldwater fish and overstocking them in a small tank that is warm will lead to problems.
I have a 5 gallon planted with 1 betta and snails and ammano shrimp. It is a fun little tank and very low on upkeep.
i have a spare 5 gal and would like a betta would i need and heater as i'm in england and temp can get as low as 20 degrees celsuis also have you a filter, the shrimps sound interesting how big do they get and have they any special requirements.
I would add the heater to the 5 gallon. The small ones are cheap and it is just safe to do. I used to keep bettas in unheated tanks but if the heat went out I always freaked out. Much better this way plus bettas do like it on the warmer side.
Amano shrimp and ghost shrimp are fun additions and don't get over 1 inch in size. The clean up scraps and sometimes eat algae as well.
Well if you want to go with coldwater try creek chub. They would be hard to find this time of the year but they are free and if they got too big you could put them back in the creek. I had some in a 10 gallon tank along with a crayfish for about a bit over a year. They'll eat anything and require next to no heater. You do need a pretty good filter though. crayfish make a mess.
I would be really careful about grabbing things from the wild and placing them in any aquarium...and if you then put them back into the wild. In many areas of the US, and other countries this is illegal.