help fast pls Can i change focus school later?

[Sam]

just ended second dream and i have to choose one school, can i change later? i want to pick up unairu but internet says everyone picked zenurik

[peppermint hollows]

Yes

[Sam]

thanks man

[Kittenpox]

Yep. Simply obtain a focus Lens, and equip it to your max-rank warframe/weapon(s). As you obtain Affinity (experience points), a small portion of that will be converted to Focus. Look out for the yellow Focus Boosters in maps.
I'd recommend looking at the Bounty rewards from Konzu in Cetus, for lenses. There are better quality lenses (more focus gained), but those should at least get you started.

If you want to go for a specific school, I recommend putting that type of lens on your warframe. (I also recommend putting that type of lens on your weapons, but do the Warframe first - because it'll likely contribute towards most of your Focus.)
When applying a lens, it'll replace any existing lens on an item and the previous one will be lost. But you can have at least 4 lenses (warframe, primary, secondary, melee) active at once, and if you've found spares there's no harm in applying them to stuff you tend to use often.

As for changing schools, you'll initially require 50,000 Focus (of that school's focus type) to unlock a school, and then points can be put into it as normal.

Personally, I started with Varazin because I liked the idea of the Rejuvenating Tides passive (health per second), and I mis-interpreted "Way-Bound" as meaning it could only be used while that was my primary. If I've read correctly, I can still get Rejuvenating Tides as a passive irrespective of which School I've got as my primary - but it'll require a LOT of invested Focus points to make that happen.
So, since then I've switched to Naramon and am putting points into Affinity Spike - with the goal of doing stealth melee kills for bonus Focus (partly from Affinity Spike, partly from the bonus Affinity from consecutive stealth kills).

There should be more information about this stuff on the wiki. :-)

[[F8L] Mycrus]

yes and because of waybound passives you are encouraged to go through all the schools... i like naramon + madurai because after you unlock all the passives and primary naramon you can make 6 max distance void jumps to traverse poe easier

[primobrainlet]

Yes

and zenurik is very overrated, pick whatever sounds cool to you, the only I would really avoid is maudari