Recommend you watch, learn, and complete the exercises for Early Math, Arithmetic, Geometry, and Trigonometry available online from the Khan Academy. Complete the above Math Subjects in the order listed. If you already know a given subtopic, after checking out the content, press forward.

Starting with Geometry is not the best course of action, IMPO, until you are comfortable with addition/ subtraction/ multiplication/ &division for both decimals and fractions. Learning to effectively operate a tape measure and other layout tools, first requires a solid working knowledge of decimals and fractions.

As a former volunteer tutor in Math/Algebra, can tell you first hand that Khan Academy + your level of effort/dedication into the "journey" will yield positive results for you. You must invest the time and step through the saturation ~ incubation ~ illumination phases to truely master most challenges in life.

Good luck.