Hi and welcome back!
There are several solutions you could use - I personally have a wired solution:
http://amigakit.amiga.store/product_info.php?products_id=116This comes with the Genesis TCP/IP stack.
Whilst there was a wireless version of this card available from Amigakit it no longer appears in searches on that site (I suspect discontinued, but they can confirm that) but if you Google it the "old" webage on Amigakit can be found if you want to take a look.
I personally use the Roadshow TCP/IP stack, it has command line control (which suits me fine - Genesis has a Workbench config program which most find simpler) but is easy enough to setup and people here can help you with that. Works brilliantly for what I need (surfing the web occasionally and accessing my PC for data transfer).
If you still have Miami you can continue to use that, I used it too for dial-up back in the day but have lost the hard disk / serials for it.
Other wired solutions include Plipbox (wired solution, uses the parallel port) - I read good things about it. I personally still use the parallel port for several other connections so have not tried this myself.
A friend put me on to this wireless solution via PCMCIA but I don't personally know anyone who has one or tested it:
https://retroready.one/products/wifi-cards-netgear-wpa2-aes-amiga-a600-a1200-pcmcia-wifi-wlanSo there some things to get you started. Happy to help you get setup, if you need anything just post.