Let's start with WiFi  since that's your gateway to pretty much everything else. Every computer, tablet, and phone these days lets you browse local networks. You will probably need a password, but it might be easy to get from, for example, the cafe's barista or the hotel's front desk. But be wary about connecting to networks that don't require a password, especially at conferences. They might be run by someone trying to spy on your internet activity. Once you are on the Internet, you might want to connect to your company's protected network through a virtual private network or VPN. 

VPNs  could be complicated to set up in the past, but if you have a good IT proficiency it is a quick process. If you don't fill skilled enough you can ask for the help of your network administrator and test them before you go on a trip. If in either way you get in trouble, you should check out the VPN troubleshooting guide for remote workers on lifewire.com for helpful tips. However you get on the Internet, be extra careful about the information you send and the information you carry with you. Laptops and flash drives do get stolen, so encrypt or password-protect anything that is sensitive, activate dual factor identifications and use a password manager software. 

For phone service, there are two common problems. You might find yourself in a place without service, and there is not much you can do about that. The second problem happens when you go to another country and find that your phone simply doesn't work, perhaps because your subscription is invalid there. That can be fixed by buying a short-term local subscription and then installing its SIM card. In many countries, these are widely available at airports, convenience stores, and supermarkets. A better way if you have a fairly modern phone, you can purchase a ESIM through providers like Airalo or similar. The advantage of ESIMs is they are cheap and you don’t have to physically remove your SIM card from your device. HERE is a list of phones supporting ESIMs . In the end, the problem could be your phone itself. Locked network phones would not work with foreign carriers, so if you buy a device from a network provider be sure it comes unlocked. American carriers are requested to sell phones with a 60 days lock period, so if your US device is less than 2 months old, you will not be able to use foreign SIM cards and ESIMs. 

Eventually, even if you run into any of these problems, there is an easy solution always at hand: online phone services only need a good internet connection. You can make online phone calls within almost every social network, either Facebook, Instagram, Whatsapp, Telegram and so on.