How do you auto equip mods in warframe?

Now that I'm level 2 I need to know how to auto equip mods till I figure out how they work. (Xbox1) or even equip mods in the first place.

Go to your Arsenal, select your warframe and click upgrade. Then click "Actions" pictured below.

Now you'll see a menu which allows you to start auto-installing mods.

Also, mods aren't very difficult to figure out.

Firstly "drain" and "drain capacity": The number in the upper left of the card is the "drain". Your warframe and weapons have a drain capacity. For example, my warframe currently has 14 capacity. If I equip a 2 drain mod, I have 12 more capacity for other mods.

Secondly "polarity": the symbol next to the drain number is the polarity indicator. There are at least seven of these. Slots also may have polarity. Based on whether the mod matches the slot's polarity, you get the following outcomes:

Slot has no polarity: no change to drain of the mod.
Slot polarity matches Mod polarity: decreases the drain of the mod.
Slot polarity does not match Mod polarity: increases the drain of the mod.

So you want to match polarity to be able to equip more mods.

Lastly Fusion: When you unlock the mod station in your ship, you can power up mods by spending credits and endo. This is called fusion. Each upgrade to the mod increases its effect and its drain. Keep your warframe's drain capacity in mind when upgrading so you can still fit all the mods that you want.