Which Raspberry Pi board do you recommend?

Which Raspberry Pi board do you recommend?

I bought a raspberry pi pico, will it be able to do most of my projects?

We need to know what projects you plan on doing to make any kind or meaningful answer.
The PICO is a Micro Controller, while a Raspberry Pi is a Single Board Computer. How each of them do what they do, is quit different. And how you set them up to do something is quit different.

I do projects by using some small components and serial screen, I plan to do some small projects for smart home, done by sensors, servos and so on.

I would think a PICO or Pi should be able to handle that. I’ve done a bunch of stuff with Breakout Garden, Pi and PICO. Sensors and SPI screens.
Servos can be a bit of a pain trying to control them with PWM. And most want 5V for power. That may end up being an issue with a PICO.
I have two Pan Tilt camera setups that use the Pan Tilt Hat. It makes controlling them mush easier.

I used Raspberry Pi pico recently in a project, I plugged the Raspberry Pi pico into a driver board, because I need to drive a lot of things I think it is more convenient.

I’ve done the same thing with Raspberry Pi’s, pHats, Hats, Proto boards etc.
I’m also beginning to do that with PICO’s