Data is your friend. Nothing eases a trip abroad like being able to access the internet for maps, booking accommodation on the fly, gathering information … especially if you are not very good at planning ahead!
Now most hotels and some public transport will have Wifi access and of course there are always fast food restaurants. If you don’t want to spend you time in McDonalds just to get on the internet, it is worth investing in a data plan.
Depending on your phone contract, you may have some roaming data included but if not, and your phone supports it, an eSIM is the way to go. An eSim is essentially a virtual SIM card that you install on the phone and load up witha data plan. Some bank accounts such as Revolut support these, and there are apps like Saily and Airolo through which you can purchase region specific data plans. They are usually pretty reasonable. I have used Saily a number of times, but it is worth shopping around.
[Side Note: If you are planning to use public Wifi, I would very much recommend a VPN for security. I use Proton VPN, but other VPNs are available!]
For navigation, it is possible to get offline maps such as OpenStreetMaps, but Google maps is still the best. Bare in mind that if you are planning to head to remote locations (especially driving) you are likely to hit places where there is no signal so it is always worth
Downloading the route before you set off - Google Maps has an option for this,
Having a reasonable idea of which roads you are likely to want to travel down
Having a paper copy of the map just in case