Have to admit, BCH's marketing ability is really tough, and compared to bitcoin, BCH cheaper, in relative terms. So investing in BCH may yield more revenue.

if you just start, you should start with BCH or ETH, better and easier for you my friend

Yeah bitcoin is the most popular than bitcoin cash, you can also invest in bitcoin cash if you have a lot of money to invest. But for me i will still choose bitcoin.

From my own point of view, it is always better to start with BTC than to start with BCH. You can learn many things from it if you know where to look and I treat BCH as an altcoin of BTC. Don't get me wrong, both of them will provide you good profit if you enter in their lowest prices but I really think that you should go with the basic first and that is Bitcoin.  BCH is also very prone to extreme pump and dump that might procure huge loses on your side.

Personally I wouldn't invest in any fork (bitcoin cash, bitcoin gold) just stick with the classic currencies, if bitcoin will go down it'll bring bitcoin cash with it but if bitcoin cash would crash is unlikely to bring bitcoin down, in my opinion.

I did my share of research.
1.BCH is trying to decrease transaction time by increasing block size. This is a main feature.
2.There are some secondary improvements but its basically same old BTC.
3.Its pragmatic decision from business point of view, transaction time is very long on BTC, it had to be dealt with. BCH doing something to resolve problem while BTC is stuck with old implementation because it has huge hashrate and its hard to persuade all the miners to change something.
4.The main problem they should be solving is block propagation, block time is depending on ability of network to deliver block to all nodes. This will decrease transaction time without affecting verification algorithm. LTC for example is faster because it uses different network to deliver blocks.
5.There is actually no explanation why block time for BCH is 2 min now. It just works empirically. I think BTC can also implement "advanced dynamic  difficulty algorithm" and speed up network , and it will hold , but network will be less secured and 51% attack will be easier.
6.The only protection we have is hashrate, at this amounts its hard to imagine who can hijack network it will cost billions of dollars.
7.So BCH is more pragmatic and more risky, BTC is more conservative and secure.
8. In short term BCH have a good chance to grab market share, and they are flexible with business demands, in a long run they are the same. I would say LTC or Doge have more to offer in terms of innovation.

I would still choose to invest in Bitcoin over Bitcoin cash even the it has expensive transaction fee. But when it comes on investing in cryptocurrencies it is always best to diversify, so why not invest in both? It is always the right time to invest in cryptocurrencies if you are going for long term investment, but better to wait for a dip if you want to do short term investment. But since you still don't have any experience investing in crypto, I suggest that focus first in one coin to invest and study how the flow of the market and the best way to start is Bitcoin.

Now most of the top listed altcoins dumped little in the market place list. If you want to invest your fiat cash to cryptos this is the perfect time to invest your fund and you will get the profit with in some days. Please select the cryptos according to the price graph movement completely grows in the market for long time.
In the comparison of bitcoin and BCH. bitcoin will be the all time perfect option to find the profit in some days.

long term bitcoin and only bitcoin and nothing else.

short term bitcoin but also at specific times bitcoin cash. and also by extension all the other altcoins out there.
now this "specific times" that i mentioned is the times when the whales are advertising these altcoins and pumping them hard. in 99% of the times, this happens during the times that bitcoin price is stable. like right now that bitcoin moves up and down less than 10%. during times like this every trader looks for altcoins to pump and make up for the time by gaining a huge profit.
they move from coin to coin, so don't get stuck with only one all the time.

bitcoin cash is a better investment than investing in bitcoin. Always choose the options in the current instead we should choose bitcoin cash for the future potential.