Car will start sometimes but then sometimes it will only click when I turn it over

We need to start with the battery first. Have a look at the terminals for excessive corrosion, usually will look like a science experiment with all of the white chalky material on top of the terminals. If they look like this you will need to loosen the terminals from the battery and clean the terminals really good. They sell cleaners for this, but the way that I do it is to rinse the battery and terminals with water first to take off the crud (for lack of a better term), then with an old cup mix 2 tablespoons or so of baking soda and fill the cup with water and mix real good, then pour it on the terminal ends and carefully on the battery because you don't want any to seap into the battery because it will neutralize the acid inside. Now if after cleaning it still does the same thing, go and get your battery tested at your nearest part store because most of them will check it for free. I will attach a guide that we have for battery issues and no starts.

https://www.2carpros.com/articles/symptoms-of-a-bad-car-batteryhttps://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked