If you are using 3d rendering software there is a TON of free stuff out there.
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Those are two of the better quality sites with free stuff. There is also the Daz store.
A lot of the 3d objects look kind of crappy when you import them but throwing a new material on something can really make it look like assets that your would otherwise have to buy.
Also, depending on what you want to make there is also Unity engine. I started with Ren'py and it is very easy to learn but would have been a challenge to implement all the things I wanted to in the game like time (down to the minute), inventory and more complex attributes.