Late reply to this, but I hope this helps you out.
Here is my input. Don't play against a variety of players for now until you learn the basics of the game. Go to YouTube and look up tutorial videos, they generally are fairly friendly and tell you what to do with button inputs assuming you are familiar enough with the 1, 2, 3, etc. directional input. A few good ones I used when starting out on Melty are:
http://www.youtube.com/watch?v=Sbqaak52pjc (Ciel)
http://www.youtube.com/watch?v=UWggitBqiPo (Aoko)
http://www.youtube.com/watch?v=CBoT4DbKPFM (Hisui)
These ones are all put together by ikusat, who did a damn good job in my opinion. These are all outdated at this point, as far as the effectiveness of the combos, but it will definitely be useful for starting you on your way.
Stay in practice mode just pulling off these BnB basics that the videos guide you through. When you can get the combos down consistently and fluidly, you'll know that you have the basics down like jump cancelling, shield cancelling, A-whiffing, jump B-C, etc. If you have trouble pulling off the stuff in here (from the basic BnB parts only) then those are what you need to work on. The advanced tutorial section in Ikusat's videos tend to be rather strict in your frame timing and can still be difficult for an advanced/experienced player to pull off, so don't fret if you can't get those down immediately. Remember that these videos are out of date and will not work as well as they do in the tutorials with the more recent patches to MBAC.
After you are able to pull off the basics against the computer in practice consistently with other characters, I would recommend going back to your character and learning what each of their moves are from the basics (2A, 5B, 6C, jC, etc.) to the command input ones (22A, 236B, 214A, etc.) and then watching combo videos for that character. If you are familiar with what your character can do, then you should be able to read the combo videos to a degree and it will give you an idea of what you can do with your character.
Don't spend too much time with other players in netplay as netplay can be laggy at times and if you jump from opponent to opponent, they may not be able to help too much as you are just getting beat in repeated matches. Melty Blood isn't that beginner friendly in learning from getting beat on, it's a fast paced game in which you can lose half your health from a single combo if you don't know how to reduce damage properly or tech properly and that can be discouraging to newer players, so I recommend practice mode to hone your skills and to start from there.
After you know your character's basics at least and are able to pull off the basic techniques of the game: shield cancelling, jump cancelling, etc. join the Melty Blood IRC channels and get advice from players in there, their input is much more beneficial if you can actually put it in effect without too much trouble. Additionally, having the game windowed while in IRC is good as well so you can switch back and forth when someone tells you something to try out. Finally, after you feel comfortable with your character's basics, skills and abilities, take your game to Netplay and take on other players.
When you lose to an opponent or if you repeatedly fall for the same combo, ask your opponent for how they started the combo: is it a tech punish, is it a high-low mixup that you need to watch for, should you opt to shield instead of block to avoid frame traps, how to avoid sandoori, etc. Ask your opponent on how they do their combo on you that you fall for, ask what to look for on how to avoid it next time; since it is a combo your opponent does, chances are very good they also know how to block the same combo/not get stuck by it. Me, when I play against another opponent, if I fall for the same stuff over and over, I generally see the mistakes I'm doing, but if not I ask them what I'm doing wrong and what not to do next time. Granted, I still consistently make the same mistakes even after being told what I'm doing wrong, but at least it will allow you to see what you are doing wrong because once you know you are doing it wrong, each time you do it you realize you messed up the moment you do it. It's good because it will eventually get you to stop doing whatever it is and gradually hone your playing to a more refined play style.
Hope these tips will help out your game and get you on the way to being a better Melty Blood player. There are various Melty Blood tournaments and events held by fans of the game where you can go to get advice and tips from players in person, or if you are in luck, there may be players nearby where you live that would be willing to help out a newbie player, I recommend checking out the
Regional Community thread here on the forums as well if you get a chance.
Good luck with it.