Despite its similarity, the latin word patientia doesn't have the meaning of "patience" as the virtue or ability of waiting, but means more the virtue or ability of suffering r bearing something. How can I say in latin "have a little patience"? Is there any way of expressing this concept in latin?
You may be able to express the “modern” sense by saying patientia morae (or morarum). Similar constructions are suggested by Georges for impatientia and impatiens with a nod to Sil. Ital. 8, 4; Ammian. 28, 1, 9; Tac. Hist. 2, 40; all of which use the adjective impatiens. Generally what this tells me is that you might be better advised trying to find a different way to express whatever it is you want to say.
In the case of “have a little patience,” I gather this is intended to mean “wait a little while.” In that case I would translate it as paulisper exspecta.