Training your voice requires a knowledgable trainer. You need a good voice coach

Depending on your age you may still be going through puberty and have an immature small larynx and therefore you can not produce the slower frequencies for a low sound.
More information is required from you to ensure a safe and sure answer.
Do not just sing and think you are practicing because you will more than likely damage your larynx through bad technique.

THE ONLY SAFE way to learn the correct singing techniques & to improve properly IS to take OFFLINE face-to-face singing lessons with a fully trained vocal teacher (in case you do not have a teacher yet)! The teacher HAS TO BE in the same room with you, so that he/she could give you proper feedback.

Please do NOT rely on any dodgy web tutorials because that way you can misunderstand things VERY EASILY and develop bad habits, hoarseness, vocal nodules and other nasties IN NO TIME, and even though you would sound good! It is always much wiser to invest a little bit of your money/time to face-to-face lessons rather than wasting the same amount of money (or even more!) to frequent ear-nose-throat specialist visits due to aforementioned problems, so please reconsider this. If you can't afford vocal lessons, then joining a choir is the only SAFE alternative option. And believe me, but even MANY of those who have music as their hobby DO take lessons as well!

Always remember to warm up your voice properly, but please know your limits and don't overdo your voice! Remember the diaphragmatic support, do not strain your throat too much! Also, remember good body posture!

Avoid fizzy drinks (burp danger), dairy products (mucus risk), caffeinated products (coffee & tea included, they dry up your throat) and spicy food (irritation risk)! You can consume these things, but NEVER before singing!

Do NOT shout, yell, scream nor otherwise abuse your voice AT ANY TIME! Also, please respect your vocal range; if your teacher says you are, say, more of an alto (baritone if you are male), then you ARE more of an alto (baritone).

DO NOT try to imitate anyone famous, that will usually give you just bad habits and even damage your throat. You are YOU and your voice is unique, so please learn to cherish that. The world does NOT need copycats.

Do NOT sing, whisper, shout, yell nor scream if having a sore throat/cold/flu, Also, do speak as little as you can if you have flu/cold/sore throat!

Remember to drink at least 2 litres of room-temperature still water every day, not just during singing days!

Smoking is a big no-no, as is inhaling secondhand smoke. Also, avoid staying in dusty and/or moldy environment.

Dear Steph, You may not think you sound good, but are you sure? This is exactly where singing lessons might come in handy. Yes, a lot of people are naturally endowed and drawn to singing lessons. I think your curiosity and need for knowledge is altogether justified, and that going to a professional teacher will give the best answer.
Do you know people who sing-as in church or school or community chorus? Ask them for recommendations. Some teachers allow a visitor into private lessons ( it would have to be a very good friend of yours) to get an idea of what a lesson is all about, before trying one out for yourself.
Be cautious- not overly, but common-sense cautious, about someone who wants to promise you the moon and stars in five easy lessons on the one hand, or someone who insists that you sign yourself into slavery with their method only for the next 6 years on the other. Seek out someone who has a willingness to deal with various styles of music. Don't fall for the most expensive price tag.
Is there a college or university in your area with a music department? Often you will find students of singing to give lessons at a lesser price than the full-fledged teachers use.
We are all born with two legs ( except for a small minority) but not all of us put in the time and effort to become a track runner. Were we to train,even a bit, we would notice a distinct improvement in our ability to move about. If it gets us to jogging daily, what a gain for one's health! And who knows, it might lead to a yen to train for and try out a half-marathon. So we are born with voices ( except for that slight minority). How many train them? Will it lead to the musical equivalent of a daily jog, or spur us on to marathon level?
Follow your curiosity!
Best wishes and keep on singing.