The way to do both voices is similar, to do gollum you have to be more forced in your voice and have a tighter chest, be a lil more relaxed when u do venom
Um let me give you a trick to do it easier so u can use honey and water so what you wanna do with the honey is put in in a spoon and put it in your mouth for the water you need to drink it and swallow it that’s it and there we go new venom voice edit: I tried this and it worked!