I'm going to be as helpful as possible. Because when I sought these answers I just got another glimpse that people are cunts. Pardon if I insult your intelligence, I'm an idiot, so I'm writing in a way it would have taken me to understand.
sign up for interactive brokers. They have 2 dollar future trades, That's better than anywhere. You hate the interface at first, then fall in love with it. It makes a lot of sense once you get the hand of it. Before that, feels like too many buttons.
go to "permissions" in your account manager, request permission for futures (and options too if youd like, and anything else you fancy, like bonds and fx and foreign equities). the prompt will ask you your experience and goals. say the right things. In a day or 2 you will get the green light. My experience is nil and I got through this hoop.
To to Classic TWS pase. Type in "ES" in the CONTRACT column. Then scroll down to "emini sp futures. click on it. Then a screen will ask you to pick a front month or back month future. You choose. Just know that these cme eminis roll over at expiry into the expiry period. So you don't have to sell close to expiration.
These things trade almost all the time. The schedule is listen in a bunch of places, but if you right cliick you contract, look around, you'll see the hours.
A ferw things to keep in mind is overnight and maintanance margain. IB tells you what they are.
IB also has a link with all the American options and their margin requirements. You can go into Permissions if you want to trade derivative in other countries.
Here's the link that I'm sure you'll be referencing a good bit. If the fucking govt didnt limit overnight margin like they do, a lot of folk wouldnt even both with futures.
Remember too that theyre taxed differently. Mared to marked. 60% long term, and 40% short term. Check it out.
Here's the ib link
https://www.interactivebrokers.com/en/?f=margin&p=fut
p.s. I sound like an ib fanboy. It's just all I know. If there's a better option, somebody lemme kno