Yes , a good idea is to research bitcoin on your own. That way you will understand what is all involved.
One of the most important things is not to invest more money than you can afford to loose . And that goes for every investment in this world .

When you make you first buy , don't spend more than $100 .

Read everything on here ,and look for articles on google .

If you are depending on others to get you started ,you wont know what to do without their help .

You probably will sign up with a bit coin exchange , before selecting one , google it's name ,and read the reviews .   

Good luck kid ! There have been tons of money made and lost with bit coin..

Your luck is the same as anyone else on here . 

Oh , last don't buy or sell because of what your read on any forum, no one knows what bit coin is going to do in even the next day.

Complete newbie?

Start of with the very basics : Babypips.com will be sufficient for the basics of the basics.

Start with small amounts and dont go haste with bigger bankroll or capital.

Lots of trial and error much needed for you to learn. Beginner tips? Dont be greedy. Dont easily fall to fuds and fomos.

Strict capital handling and risk management.

It’s really nice that as a young boy you’re interested in investing your money in places where it will be useful to you in future. If you’re serious and invest your money for long term in Bitcoin, by the time you finish college you’re going to have a huge amount in your wallet where you’re holding it, because from now to then, the price of Bitcoin must have reached a really high point by then.

My only tips is that you should invest in what you can risk and don’t be greedy, after investing, try to focus on other areas of your life like your studies while you wait for Bitcoin to increase.

you come across the right act, where you ask in the right forum too. for that I only suggest that you, at least before plunging into real trading, maybe there is no harm in trying some Demo trading first, to hone your skills. I am sure, with a youthful spirit and spirit it will be very easily absorbed. you just have to do it diligently.

1. How did you start trading Bitcoin?

I didn't, I earned them. Never bought a single satoshi, though I have basic knowledge about trading, but I used to trade Bitcoin against other smaller cryptocurrencies.

2. How can you start trading Bitcoin?

To be honest, Bitcoin is not a cryptocurrency that can be traded on daily bases to get profit, but it is an asset that increases in worth in longer terms. People usually either buy Bitcoin and store them, or buy Bitcoin and trade it against other smaller cryptocurrencies in the market to earn profits regularly.
But, if you still want to do that, you can always buy with a small capital from any exchange that supports the payment system from your country, and then trade Bitcoin against USDT (A form of dollar in cryptocurrency, that is always stable).
The process of trading Bitcoin would be to buy now and sell it later when the price is higher and you are getting more than what you've spent.

3. Tips for begginers?

Don't invest everything you have. Always start with the minimum if you are not experienced.

Never panic sell. Don't read messages and news and sell your assets based on that. You never know what happens, and you will always be in loss if you do that. If Bitcoin drops $2,000 today then it can gain $4,000 tomorrow. The market is so unpredictable, so make sure not to fall into such things.

Be aware of scammers. Always use trusted services whether you are buying or selling, always do your research before doing that.

Good luck! 

I've started trading in small quantities, so the potential failure is negligible. Well, I'm still trading for small amounts, but at least I'm doing it more frequently now. I'm still not comfortable trading in high volume.

There is no so much answers in your question because that is a Basic , you are asking for Investment meaning you are ready to HOLD and RISK right ?

So what you need to do is Buy Bitcoin and Let it in your wallet , Buy in legit Exchange like this

https://www.binance.com/en

 and Save them in your trusted wallet , but of course better to have your own Nano Ledger since you are a HighSchool and will keep this coins for long years i guess.

Happy 2021 and Happy Investing , NEVER BECOME GREEDY , and NEVER BECOME PANICKER .

People trade to make revenue, and myself started trading to sell off the rewards. Initially I wasn't much into campaigns, and mostly I participate on bounties. Once after the payment is received I used to wait for months. For some bounties it has taken years to get listed on the exchanges. I used to wait until then, and further sell the tokens. In those days I never looked for profit, further slowly learnt about the process of trading to make profit.

As beginner you need learn more first about how to earn in bitcoin and to different ways and what you need to avoid to prevent losing money because once you are beginner you are prone losing your capital funds so we are here to help you until you learn a lot of knowledge that you use here in the crypto world.

You do not a big capital for starting but you need to know how to reinvest the profit that you will get in investing and trading until it become bigger and bigger this is what we do most of here.

Of course you can do that, but you must first learn a lot about trading. I do not advise you to trade or invest any capital before you learn well because you may lose all of your capital, you can follow many sites and channels that teach trading and then try trading with a small capital at the beginning .
The most important advice in trading is patience and avoiding greed, greed and impatience are the worst traits of a trader that may cause him a lot of losses.