You’re obviously new to coding, and new to the Blynk community.
Developing, testing, debugging, maintaining and improving a project like this is a major undertaking. It’s not something that a beginner should tackle, and it’s not something that a friendly community member will knock-up for you in an hour or two on a spare evening.
If this is a home automation project then using a single NodeMCU with a multiplexer most likely isn’t the best approach. For sensors to give meaningful results then they usually need to be in physically different locations around the home. If this is the case then running long wires carrying analogue signals isn’t practical or desirable.
You’d be much better-off using a modular approach where you have one sensor per NodeMCU, and have the sensors talking to each other either via the Blynk server or using MQTT messaging. If it’s a system that needs to work even when the Internet is down then you’re going to need a local Blynk server, or a local MQTT server.
You need to learn how to write C++ code, and start experimenting with small projects. If you go for a modular approach with dispersed MCUs then it’s easier to practice with one sensor then expand your project.
You should also use decent sensors, rather than the crappy DHT11 or DHT22.
Here’s the approach I take with my home automation system:
Pete.