Play a lot. Keep records if you'd like. Join your local chessclub.
If by the book or by teachers you can learn certain basic principles,
it may help you remember your lines as you find them more logical
with a greater understanding.
hi,
Play a game on a chess board. Once the game is finished, try to replay the game with the help of the moves you have memorised. This will increase your concentration in long run.
I suppose memorizing sequences isn't the best idea. Try to pay attention to principals and make every move count, don't just go for the exchange, don't blindly move, check yourself and make sure you are adhearing to the basic principals of openings, and of middle/end game chess. You will learn eventually and then you will take a liking to certain openings that you read about, but before you dive into such things you just have to pay attention to principals and play a bunch of friendly games, games against people of all skill levels, and make note of how you win or are defeated.