40 Gallon Tank for 4 month old Corn?

I got my 4-month-old anery black corn snake a couple weeks ago, and had a 10-gallon tank for him I picked up at Walmart where I live. It's one of those crappy aquariums with the lip at the top, and I bought the additional screen top cover for it. I quickly learned that I did not want this as a tank mainly because it's very insecure I had clips and still even have to put some heavy books on top to make sure he doesn't get out. And the worst of all there is a lip at the top of the tank right next to where the screen is and he would always go up there and not come down. I fixed that problem though with putting some foam up there and at least that's fine now. It's just ugly and I hate having to put weights on top and still even worry that he might somehow find is way out even though it's not very likely.

Disregard that whole first paragraph if you want lol but I looked into the Zilla critter cages and there was a store nearby that sold Zilla stuff for bearded dragons. I was gonna have them order me a critter cage but they only could get 2 sizes the 30x12x12 or the 40 gallon 36x18x16 or something around that. So decided to just get the 40 gallon because it wasn't that much more money, and it's bigger but only by 6 inches long which isn't that much.

So basically overall should I continue to deal with my annoying piece of crap 10 gallon which I still have him in. And worry about him getting out and having to look at this ugly thing with weights on top. Or can I move him into the 40g which has nice sliding door and secure locks. I have read online they get scared in too big of tank but also have heard those are lies. I just wanna know whats the best idea. If its not gonna hurt him at all I'd like to use the 40g.

I'd say it's less of a lie and more of a misconception. Big OPEN spaces cause stress. As long as you add enough clutter inside that your guy doesn't feel super exposed when he's out and about, it should be alright. I would be nervous about not having a secured top too. I've heard a lot of escape stories that start with "I stacked some books on the top".

The 40 gal switch sounds like a good idea to me.

Thanks! Yeah I have been ordering stuff to put around inside the tank, I'm gonna make it nice before I move him. And I have a clip on one side because the other broke, and these are 2 heavy college textbooks weighing about 8 pounds together. I mean I would think a baby isn't strong enough to lift that! Either way still not the best idea don't wanna end up without a snake at all.

Appreciate the help!