There are some fundamentals that everyone who wants to draw needs to learn. (Not in order of importance).
#1 Control exercises
Make yourself comfortable with a pencil and paper, draw straight lines - 1/4, 1/2 and full width of a paper - draw 5 times over each line and try to hit the line as precicely as you can. Same thing for circles or ovals. Draw 2 Lines and fill the space between with - as perfect as possible - circles, or ovals. For very small things it is ok to "draw from your wrist", but try to train to keep your wrist still and rather use your shoulder and elbow to make the movement.
Learn about 1-/2-/3-point-perspective and vanishing points. Start with very simple forms like a cylinder or a cube and draw them from different angles. Put some simple objects on a table and draw these forms in a composition. Try to draw some stills with more complex objects, or use some photos of streets from different views.
#3 Shape and form
Start with simple objects and try to create more complex forms. You can draw some random "blob" and try to define a 3 dimensional shape by drawing contour lines in that form. Like a wire frame.
#4 Value and Light
In order to create convincing 3 dimensional forms you need to control your values. Always start with black and white. Use a simple value scale of 5 values. White is the lightest, black the darkest 50% grey the middle. Learn to understand highlights, reflected light, core, cast and occlusion shadows. Add more lights and complex forms.
There is a ton of really good resources online to learn anatomy for artists. Get a book about it - I always used this: The Complete Guide to Anatomy for Artists & Illustrators from Gottfried Bammes. I cant remember the Website but when I trained figure drawing, there was a site where you were shown a picture of someone in a specific pose and you could set a timer for how long you wanted that picture to be shown. Train to do poses in 10s, 60s, 10minutes.
Depending on what type of learner you are you might want to search for some resources on each topic, get some books or just trial and error. Always use some reference even for relatively simple things.Get a sketchbook and carry it around. But most importantly have fun !