I managed to score a closed box GoTrax Transit for half the retail price so I’m wondering what else I should get for it.
What’s a good bike lock so I don’t have to worry about it getting stolen? Are those U locks still easily pickable with a pen? Any cheap options out there for a rear rack and saddle bags? Lights? idk, what do I need so that I can keep it maintained? I’m on a tight budget so I’m looking for the best deals that I can get by with. I want to be able to use it get groceries and run local errands.
Also, do you take your batteries inside stores with you? I saw a lot of bikes on facebook marketplace with their batteries missing because they were supposedly stolen. Makes me think I should make a custom bag for it so I can carry mine around.
I do wish I had gotten one earlier, it’s a lot of fun. A little too much fun. I worry this is going to unlock a yearning for a motorcycle. 
I get my lights from aliexpress. You can get away with gloves and bottle cages from there too.
For some bags I’d maybe go with ones from an actual bike store as aliexpress can get a bit too cheap. I have some nice Ortlieb pannier bags but one thing I realised is depending on you needs you could get cheaper pannier bags that stay on the bike and put backpacks or shopping bags in them. It’s a cheaper option if you don’t want to go all out on bags.
The recommended combo for locks is a D lock AND a chain lock for your bike. Depends on your area and how safe it is. Kryptonite is the best brand, Arbus is the most universal. Buy the best you can afford here as a few hundred bucks in good locks can protect a couple of grand of bike.