Thx all for your help,
I rode all the documents and guides you just told me, I have my back up (private keys) export from Bitcoin.com wallet on my desktop.
I followed the instruction to import private keys with Electrum, here I am:
on Electrum screen, it ask me to enter a list of private keys, so I copy/past my backup from bitcoin.com wallet (text format), and electrum doesn't recognize the keys I guess? cause I can't click on the "next" button.
sorry, a bit confusing for me

never share your private keys with anyone. just check the following yourself:
1. check if your keys start with any of the following letter: '5', 'L', 'K'
2. check if each key is 51 or 52 character long
3. when you enter them in that textbox make sure you are not adding any extra characters such as ',' or '.',... each key must be entered individually and separated others with a new line (press enter between them)
if you followed the above 3 and still didn't work (for instance if your keys start with a different letter like "6" or "xprv" has a different length) then tell me
that first letter only, it might be encrypted key or an extended key which requires a different approach.