If you don't have much experience with herps in general, I would not reccomend trying communal vivariums yet. I would reccomend keeping each species separately for a good amount of time to truly understand them. After many months of keeping and researching with all the proper setups would I advise cohabitating.
Instead of separate species being housed together, you could try anoles or frogs, maybe even amphibians or water based species, many of which can be housed together.
For now, these are some reptiles (Same species) that could cohabitate. Although, for some, such as Leopard geckos, this could still be risky, I don't reccomend it. Many also have to be only female unless you want breeding.
•Leopard Geckos
•Pygmy Chameleons
•Anoles
•Long Tailed Lizards
•Mourning Geckos
•Etc.
Mixing should never be done as a cheap option to save money, have more animals, etc. More often then not animals will get eaten or too stressed out to eat and get sick, many even dying. All animals should be kept and behaviors learned along with a huge amount of research done before considering housing different species or even the same species together. All animals should be able to be separated if things don't work out.
Good luck to you!