It's a smidge messy, due to rights issues.
Venom, and any other Spidey-based spin-offs, are separate to the MCU. The latest Spider-Man film (Homecoming) and its upcoming sequel are both part of the MCU.
The Netflix Marvel shows exist in the same Universe as the MCU films, as does Agents of SHIELD. However, there is very little crossover in AOS (though plenty of references), and there's literally the odd references in the Netflix shows. The Netflix shows are much more standalone / almost their own little universe.