Any sort of investment has it's own risks so instead of asking strangers where should you invest your hard earned money, it's best if you do your own research and make calculated investments. Since you said that you earned these bitcoins through Minor trading so I guess it's safe to assume that you do know how to trade, so just re-apply the same principal and start trading but this time with bigger investments but the safest way is just hodl them and wait for the price to go up.

As for investing in Altcoins and Lending, they have their own risks. An altcoin can lose its value completely, it has happened in past and you can lose the value of your bitcoins and Lending, even if you take collateral which on the forum are usually altcoins or accounts, there is no promise that their price will remain same in the future.

there are many ways to turn 3 btc into 4 btc in just 2 months but all methods are very risky. gambling is the most risky method but if you win in a high odd by chance, you will have 4 btc or even more in a very less time. btw, gambling is not recommended since you are taking risks with the money that doesnot belong to you. but you can still try it, if you can afford to repay even after loosing. other option can be trading with some altcoins. you can try ETC trading because it is very much in talk these days. btw, personally i think your friend is asking too much interest. if you really need a loan with low interest rates and have a valid collateral then you should ask for a loan in this forum and hopefully someone may help you. also why do you need this much money ? i am just curuous to know.

Yes Paypal is crappy , Paypal will sooner or later ask you to provide information's to confirm your identity if you receive big amounts of cash or from suspicious accounts , and they can limit your account and you lose your money even if you did nothing .
Bitcoin don't need ID,Passport , don't need a specific age , can't get limited and you can receive how much you want and also you won't get your balance chargebacked by the sender , fees are much lower and much more ...  Bottom line ? Bitcoin > Paypal .

Now if you are selling your BTC for Paypal , you may want to be caution because you can get scammed so make sure to trade with someone trusted and note that using a Middleman won't really change anything because the other party can still chargeback so it's not really recommended to accept payments on Paypal .

Yeah! This can also increase bitcoin adoption all around the world,it can be bitcoin for everyday life.

I have been familiar with bitcoin with all these ups and downs,

If the price doesn't change for a while then I'm surprised

I'm just surprised about the DOGE altcoin which increased dramatically these days after few months dying.

Nothing Much! Bitcoin has big scalability issues. Even Gavin Andersen, the guy who proposed ininially 20mb blocks saying they will be fine,
admited;

Bitcoin isn't backed by any kind of big corporation, and this is why it has slow development, along with the consensus-first policy.
However, bitcoin needs an industry-grade developer team to catch up with consumer needs.
Many proposals aim to improve scalability, like Lightning Network, but they are way too far from implementation stages. So a block increase is required and as there are infinite ways to increase the limit, there are infinite many different opinions, making consensus almost infeasible.

So don't tell me bitcoin doesn't have it's issues. If you think it doesn't, you can freely buy some "incredibly cheap coins" at 220$ per coin right now.

My first problem same with you, in my country stores have not received the bitcoin as a payer, while if it is just shop online shops. And second in my country still lay about bitcoin and also branded as criminals or corrupt currency with money laundering. therefore no legitimate decision of the government about bitcoin. thank you