The broom handle is a great first step, official or not! They also sell smaller weighted bars (I have an 8 lb one like this: https://www.amazon.com/Yes4All-Total-Body-Workout-Weighted/dp/B00XH756XY/ref=sr_1_1?dchild=1&keywords=10+lb+weight+bar&qid=1598898218&sr=8-1 that I bought for physio exercises and still use for shoulder dislocates). If you need something a little heavier than the handle to practice your form, you can also just go to a home improvement store and have them cut you a length of steel pipe for like $2/foot!
Budget Marcy Curl Bar, I've used it. Bends aren't amazing, but it's a good deal at this price point
Probably This one but not by much
how is this trap bar?
dont want a super expensive trap bar, but not total garbage either. any other recommendations?
For Canadian looking for a lower end Curl Bar. This is back in stock about 5 left.
https://www.amazon.ca/Synergee-Commercial-Bushings-Excellent-Extensions/dp/B07F89Q38T/
Additional FYI. It's marked up from $74.95 to $129.95