My advice is going to be rudimentary and simple. As you get farther along their are other people and reading materials that will be of more help.
There are other counts but my earlier experience was with hi-lo so this is the count i will use. In high low there are three possible values. These values are minus 1, zero, and plus 1.
Purchase a 4 or 5 decks of cards and a magic marker. The first open deck is to be used this way. On all 2's through 6's inclusive put a large visible plus 1 like this: +1 on the value side of the card. On all 10's, faces, and aces put a large visible minus 1 like this: -1.
After doing this you are ready for a "baby step". Put the cards face down in your hand and turn them over one card at a time. You are not going to count at this time, what you are going to do is learn the value of each card. When a 2 through 6 is turned, you simple say 1 which is +1. When a 10- through A is turned, you are going to say m1 which is -1 -- do not say minus, say m. When a 7, 8, or 9 is turned, you do not say a thing. 789 have zero count value in this system. If you use the word minus you are wasting a bit of time and memory. This first step may take a few days, but the value of each card needs to be ingrained in your mind.
After you have the value of each card completely digested, then you can go to your next step. Never attempt to run before you can walk.
The next step is to take a new pack or deck of cards that have not been magic marked and repeat step one with these unmarked cards. Make absolutely certain that you know the values of each card.
If you did step one correctly, step 2 should only take a few minutes. if not, repeat step one until you have it right.
The excitement is about to begin.
You may still use this second deck for step 3.
Once again, hold the cards in your hand and deal them face up one at a time. You are going to keep a running count. Here is a sequence of cards
Do not move your lips when counting, this is important.
Your "mind speak" in this sequence would be
Once again use the thought z for the abbreviation for zero.
This will take hours and hours of practice and will go very slowly for you at first, but this is where the money is to be made in counting, that is to say, "keeping perfect counts".
Most of us who have been counting for years still do counting drills before we hit the casinos on a trip.
When you are finished counting down a deck you should always be at z.
The part that got me excited about counting years ago is this fact: Let us say you have two unseen cards left in your hand and the count is m2, you should know that the only two cards that are left are 2 through 6. Conversely, if your count is 2 with two cards left you have a total of 20 or 21 or 2 aces in your hand, because you must have two m cards in unplayed two cards and those cards can only be T's or A's.
when I discovered that it was possible for me to predict the future with 100% accuracy, I got excited. that made me want to devote even more time to practice my counting skills.
There are more steps, probably the next one is to learn to count down your deck two cards at a time.
That is take two cards and deal them face up on the table and come up with an added value. For instance, K-Q=m2, K-2=z, 4-5=2. As you become more experienced you will not count cards like this individually; you recognize this group as a value. The example is when you see K-Q you will not say m1,m2 -- you will recognize it as m2 and simply mind speak m2.
The truth is learning to count for me was almost magical. The most difficult for me is playing indices.
So when your mind is too boggled with counting to carry on any further, go learn the playing indices.
It goes without saying, you should have Basic Strategy completely memorized before you try deviations of play strategy.
Even after all this counting practice, you are not ready for casino conditions yet. You must play thousands of hands at home under casino conditions.
This means radios, TVs, kids, and other rackets being made, while you are playing on the kitchen table or at the computer. Do not fool yourself into thinking you can play perfectly in casino conditions until you have experienced casino conditions.