Sure, assuming you're being serious.
Make sure to clean yourself out before you start unless you want a mess, a simple douche can be purchased online with ease.
When you first start, I suggest using your finger(s). Apply lube to your hole and fingers then slowly massage it to see if you like it; if you do like it, good. If you don't like it, it may not be for you. Assuming you do like it, continue to massage and probe yourself with 1 finger and sorta move it around the ring to loosen it up, if you feel comfortable, you can add another finger, but don't go too fast. The last thing you want is a trip to the ER for being too aggressive.
PRO TIP: Trim your fingernails PLEASE.
At this point, if you do like what you've been doing, I would suggest buying a small butt plug. Key word: SMALL, when you're new to this, you want to move slowly to avoid injury. When your lucky little plug comes in the mail, repeat the above process with cleaning out, lubing up, and fingering. Get yourself ready, it might hurt a bit. Insert the tip of the plug and slowly bear down on it, if you feel any pain at all, stop, back out a little, and then try again.
PRO TIP NUMERO 2: Anal doesn't have to hurt, if you go slow and use plenty of lube, it can be pleasure from here on out.
Once you've been playing with the small plug for a little while, invest in a slightly larger one, repeat the above process and go at it. Slowly. You can continue this trend of trying larger butt plugs as long as you'd like, rinsing and repeating (literally).
If you've gotten this far, you can either set yourself a limit, which is fine, and keep yourself there, or you could continue to play and get into some of the more extreme anal stunts such as extreme width play, depth play (basically a whole other realm of anal), pumping, and of course, the site's inspiration: Prolapsing.
Along the way, make sure to have fun and enjoy yourself. If you're a straight guy, definitely don't feel emasculated because you're interested in self anal play, just do it because it feels good. Be safe, be clean, and have fun.