Good idea to take a few lessons, mainly to get confidence in the water so as not to fear training alone. Once you have control in the water you might experiment with these tweaks that made my strokes better later in life in favor of basic swim class instruction.
These techniques would hamper speed for competitive swimming, but are excellent for training.
To avoid getting water in the nose hum when the face is under water, this allows for a slow escape of air which saves the breath, and water can't get in.
Relaxed bear paws instead of the tense cupped hand with closed fingers.... you'd be surprised how much faster you go, with less effort to pull yourself along (as well it feels like more chest and arm muscles are engaging).
Flat on the water:
The instruction to keep the body flat on the water is a bit misleading, and could be one reason why doctors recommend those with bad backs to avoid the breast stroke and crawl (these strokes arch the back awkwardly compressing vertebrae of the lower back).
Dismayed at this advice I analyzed my posture in the water and realized that it's not so much that we should be flat. We need to hold the body in a way that straightens the arch, yet also allows it to relax along the water into a cohesive swimming position. Once I made these postural changes I found even more ways harness the power of the eddies made by whip kick feet.
Make a half heart with each hand rather than making wide sweeping strokes with straight arms that slow you down with the drag.
Whip kick is hard and takes a while to master (much more efficient once you get it than the frog kick). You can train the feet and lower legs for this any time, even in the bath, or in bed. Practice whip kick in the water on both front and back, using figure eight hand movements to keep afloat. Keeping the knees and feet as close together as possible scoop the feet, lower legs moving in half circles, toes drawing a half heart.
With the first attempts it can be hard to get moving, but after a day or two the lower legs get coordinated and this kick permeates into all the strokes. As well the body is better positioned to be flat yet relaxed on the water, back supported.
As with running, even though the crawl is a fast stroke it can not be learned by going fast or you end up going nowhere fast and getting tired. Either in an attempt to keep the hair dry or to prevent water inhalation people often do odd crawl strokes with heads out of the water, turning it quickly from side to side, swimming with arms akimbo, all interfering with the crawl. The flailing swimmer quickly becomes tired from over exertion and lack of breathing and cohesion.
To avoid inhaling water when doing the crawl, don't turn the head out of the water, instead roll the body on to one side. The head follows the body so there's no need to turn it. There is no need to gasp for a breath because you are in control of how long it takes for the other side arm stroke to complete its cycle, before bringing you face down again in the water... to do more strokes and expel the next breath.
To avoid neck pain, when coming up for air, turn to both sides rather than always using the same side. And keep the shoulders down while swimming. The body has to be relaxed in a face down float, chin down to elongate the back of the neck and avoid stress and crunching.
Trickle breathing, odd number count and upper body:
This means keeping the head in the water while you do odd numbers of arm strokes for the duration that it takes for the air to slowly trickle out. Taking short pauses to hold the breath while the air depletes enables you to hold the air longer.
To ensure that body alternates both sides time the breaths with odd numbered arm stokes (3,5,7,9). Lower numbers for slower, higher numbers for fast plowing arms.
Learning this tip quickly made the crawl possible to do well. Let the legs trail behind (rather than fast hard kicking). Kicking is not what propels the body, it's the upper body paddling the arms that moves you along.
Once the upper body is relaxed and in sync the legs kick in on their own propelled by only a gentle shimmy from the hips that whips power down the legs into the feet.
As you work up the amount of time between taking breaths you end up paddling more strokes. When you need a breath you roll out of the water, and if necessary, recover while doing other stokes with the face out of the water. For more intense cardio spurts work up to paddling 9 strokes with a faster arm speed.
I came to see that swimming inevitably causes us to use the breathing apparatus as is in yoga and meditation exercises. I was thrilled to find this article, he so well describes this concept.