Your question is pretty open ended. What exactly do you want to do? Make beats isn't really enough. You asked about sampling instruments, but your MPC is a sampling instrument. And if you don't know if you have a memory card or not, that indicates that you haven't read the manual. Really, read this thing front to back - you bought a nice piece of gear so you should get to know it well. Sit down with your mpc and the manual and follow along, make it so the pages are all dirty and tattered with notes scribbled all over the place. That will really take you a long way.
Alright know you know how to work all the features of your MPC, then grab a beer, bud or whatever, and sit down and read through old posts in this forum, and I don't mean a skim, plan on spending hours. I say that because while I'm also new to this forum, I've realized that all the basic questions have been answered time and time again. Suggestions for turntables, mixers, monitors, sequencers, it's all here already. If you spent two hours just reading posts, you'd find out more about what you'll need than this single post is going to provide.
If you spent the rest of today doing those two things you'd know what you're doing - but better yet you'd be able to ask specific questions that wil get you respones. For example "I'm trying to decide between Ableton Live and Cubase (some version), Cubase gets good reviews, but I think I would miss not having Live's session view, for you Live users how important is the session view?" or "I'm shopping for a mixer, all I currently have is my MPC, but I envision getting a synth or two and a turntable and that's all. I use such and such DAW, and figure I'll never use more than 5 tracks. Since my price range is under $500, I found these three, which one..." As with anything, once you can put together a meaningful question you're 90% of the way there.
Sorry for the rtfm response, but I'm still new to my MPC and I did the above and it worked for me. Hope it helps you too, Good luck.
take ur time and just read,read and play with ur mpc,step by step,button by button ,but go to