I just got my very first bicycle. At 30years old, I never ever rode a bicycle. I walked into a Walmart, bought the nicest looking mountain bike I could find, a 26" Havoc Men's Mountain Bike.
My first week was horrible. Trying to balance on a bicycle, falling off several times etc. Second week, I would almost die of exhaustion from riding 400meters. Now, after about 6 weeks, I do about 5miles a day with ease.
I have now realized from a lot of the comments here and on YouTube that I was really using an entry level piece of metal. I have plans for a huge upgrade but while still learning to build endurance, understanding the little bits and pieces of increasing speed etc, any advice on what I can do right now to upgrade this present bicycle to make it more efficient? Anything I should consider doing?Anything I may have left out? Any helpful tips etc.
Leave your current bike alone, save your money for the replacement bike.
To make a significant difference to the current bike you'll probably have to spend a significant fraction of the original purchase price and face major headaches figuring out compatibility of components. Leave it original an sell it when you get the new bike.
If you do want to spend some money on making cycling more pleasant, look at some clothing items or accessories.
A few updates:
One change that you might consider is replacing tires with ones more suited to the surfaces you are riding on. I.e., if you are riding on pavement or flat good quality gravel you can fit semi-slick tires. You don't have to get expensive tires, moderately priced ones will be fine.
Keep the drive train clean, lubricated and adjusted properly to extend the life of the sprockets and chain and keep it as efficient as possible.
There is really precious little difference between new bikes in terms of efficiency. Most of it is illusory. All ball bearings have low friction. All chain drives are >90% efficient. All bikes weigh so much less than your body that weight has little effect on actual trip time.
The biggy is knobbly tyres if you have them - these actually soak up a lot of energy. A road, touring or slick tread pattern is noticeably easier. It doesn't need to be slick, it just has to have a continuous centre line. If your tyres have discontinuous knobs on the centre line and sound like a jeep when you ride, they are soaking up energy.
There is a however big quality difference between the bottom level and mid level. As AA says "Leave your current bike alone, save your money for the replacement bike."
All the above answers are valid and good. In addition to that, I would strongly advise focusing on what is sometimes called "rider fit". It is the position of your seat, seat post, handlebars etc. The big one will be the seat height relative to inside leg length. You may find that minor upgrades such as stem length dramatically improve bike feel. This will inform your decision making later for your new bike.
There is plenty of joy your new bike will give you. Wait a bit before upgrading. You need to build up experience and knwoledge and your current new bike is fine for that purpose.
This is only a supplement to other fine and reasonable answers already given. Argenti Apparatus makes a very good point that the reasonable thing to do is to replace the whole bike rather than upgrade parts of it. Henry Crun is right, your bike is fine as it is, perhaps the rough tyres need changing, the rest is fine.
Before you can make a qualified decision about what sort of bike works for you you yourself need to build up experience by riding your current bike around as much as possible. Do you enjoy roads more than off road riding? Do you like speedy downhill runs or the joy of getting somewhere remote solely under your own power? Do you want to carry some stuff or travel lightly? Is your back okay with a nimble hard tail bike or does your body require a full suspension frame?
Why is it so important?
No one but you can answer these questions for yourself. Before you feel you can answer these, or even better when you start asking yourself these questions, then is the right time to start researching, talking to other riders, hanging around specialized shops, and perhaps considering an upgrade. Ultimately, in a year, two or five, you buy yourself the perfect upgrade bike and right that minute you start considering and upgrade to that. Just like everybody does.
I, for one, have about seven bikes (I move around regularly and keep a bike or three everywhere I have a chance to do a ride), and even the crappiest rustiest piece of crap worth no more than $6 can give me a kick when the weather is nice and I take it for a spin. Getting to buy an upgrade bike is a joy in itself, but it would be a shame should it stop you from enjoying a nice ride on whatever bike you already have!
I would take it into a Local Bike Shop for servicing.
Unfortunately many high street companies will sell you what we call a Bike Shaped Object. These at best are barely functional assortment of parts. At their worse at literally death traps on wheels, with improperly installed parts (back to front forks anyone?).
A quick once over should ensure the bike is safe to ride. But again. There is very little worth keeping through an upgrade. You can probably pick up a second hand Giant (brand) Mountain Bike for less than the cost of a worth while upgrade.
However, don't dispair. The BSO did its job. It has improved your fitness levels, developed your skills, and fostered your enthusiasm for riding. Had you been told you need 500USD for a "cheap" road bike, I'm sure you would have balked and run the other way. To be honest it was a very good bargain for your well-being.