Press Shift + A
‍Go to Curve → Bezier
‍Select the curve
Press Tab to enter Edit Mode

Click a point → E to extrude (adds a new segment like freeform clicking)
Move points with G
‍Adjust curves using the handles
‍Change handle type with V

Vector (sharp corner)
Auto (smooth curve)
Aligned (controlled curve)

Fill the Curve

Select your curve
Make sure you're in Object Mode
‍2️⃣ Go to the Curve Properties
Right side panel → Click the green curve icon
‍3️⃣ Change it to 2D
Under Shape, change:

4️⃣ Enable Fill
Under Fill Mode, choose: both

Make it thicker

In object mode right click on shape and click convert to mesh

Add a Solidify Modifier