After all, many Chinese people have missed the opportunity
There are a huge lot of altcoins already. All being more or less "cryptocurrencies like Bitcoin". So your logic of missed opportunity is not good, since the altcoins have shown that they don't have the potential of becoming as important as Bitcoin.
Making a clone of Bitcoin or a fork of bitcoin are not that difficult, hence I don't expect it to be that expensive, but this will most probably not be a good business for you, you will not earn that money back.
I just want to develop an altcoin that users can mine. As for the future value, no one can predict it.
How much does it cost to develop such an altcoin?
Since you don't have the knowledge to do fixes/adjustments later on, I suggest you just mine an existing altcoin (especially if you are aware you are just burning electricity for no return).
However, even for your "make me a clone" question you may find in altcoins are people who have already done it. Just take care and avoid getting scammed.
I don’t have a mining rig to mine altcoins, I only have a computer, and I won’t invest in a mining rig to mine
If the investment is not too much, I think I can make it back, it's just a matter of time.
I successfully issued 2 altcoins in 2017-18, one of which raised 953 Bitcoins privately. However, due to China's policies, all of them were returned to the users.
One of them was listed on a Chinese exchange. This exchange was closed after running for 4 months, and some money was made.
I personally think it can be done and make money