Istarted Genshin a day or two ago and I really want to pull for Columbina ,which characters from the side banner would work decently with her

Columbina is only really good with other nod krai 5 stars (like ineffa who is the second banner), but to answert your question, fischl can work to do lunar charge reactions. But you just started so it probably doesn't matter, just go for characters you like

if you’re brand new then you won’t need a fully cohesive team for a hot minute. columbina, fischl and ifa with a second hydro or electro would probably be fine for your needs