>>411381
Before I got a proper toy, I took one of those segmented toy lightsabers, dismantled it, and used the tip segment. It has a rounder tip than something like a banana, is more long-lived than either that or a cucumber, and is bigger than a Sharpie yet still narrow enough to be very easy to use (which, living with parents, may be useful as well, since you may not always have time on your side if you're toying while they're out).
For lube, I used vaseline, which isn't the best option but it worked. Tried canola oil but I didn't like the feel, and the smell was too strong (and conspicuous when emanating from around a bed). Never tried using olive oil, and never even had coconut oil.
>>411387
I'll give him the benefit of the doubt, and assume that's not an option, and for a reason other than actually being underage.
I was in the same boat for a while; I lived in the country so no way to get to a store without involving my parents, which given how much of a shut-in I was would naturally invite prying questions about where I had gone and what I was doing.