This is my first landing page, is it good?

While this page is very good content wise, I feel it's a bit... bland. Lots of white/grey and no animation, the text isn't centered next to the images, there's a header missing above the companies listed, and I think you could frame their logos or make them clickable. Same thing with the offers, only the middle one is framed and has a colorful CTA. Lastly, you can't say your clients love you and show 5 stars if it isn't true. That's what you'll do once you get your first customer feedback ;)
Keep up with the good work, you're almost there!

I'm not a designer but I can share my feelings.

I would improve the hero animation - make the scrolling smooth. I see it is a recorded screen, which is great as it shows the real product, but at the beginning when you scroll down it doesn't feel good.

Two other minor things:

• I would add some small animations to screenshots below - either replace them with some screenshots as well or make them fade in when you scroll down? It's a little bit too static in my opinion.
• You list companies without any header. Are they your clients or just companies you like? ;-) Maybe moving "our clients love us" next to it would make it better. I would also try to get some testimonies from them, you show 5 stars but it doesn't mean anything, it's not confirmed by any real user.