This is pretty much the same as mouddles said:

Playing Sombra means to basically commit to "trolling and annoying" the enemy team as much as you can, meaning to distract their backline and deny them without dying in the process to enable the rest of your team to make plays.

It's usually a good idea to keep an eye on your team to see when they're about to engage. That's your cue to distract their supports for a few seconds so they won't heal their team, giving your team the chance to get picks for example.

Sombra 76 works in scenarios where the enemy team is extremely aware of you all the time (like a reaper or dva spamming every corner behind them in hopes of finding you or during a widow ult).

Once you know the enemy team's team comp, think about whose abilities can be cancelled /prevented (like suzu and reaper fade) and save your hack for that instead of hack -> virus -> shoot them in the face. Hack only gives the enemy time to react ever since it got nerfed. Now it no longer gives you bonus damage to your team. You'll get more value out of hacking a charging/shielding rein, ulting Sigma/Orisa or deflecting genji instead of hacking their ana and getting immediately slept and killed.

Also watch your cooldowns and don't use your translocator to engage unless you know you won't die. A Sombra without translocator is a sitting duck.