Minecraft Mods are modifications made for your Minecraft adventure, there are paid and free mods made for single player and multiplayer. You will find a wide variety of mods. for example: Decorations, Graphics Improvements, Game Optimization, Adventure, Weapons, Armor and tools that allows you to have any items without having to look for them.
The most recommended mods for you are:
OPTIFINE HD 1.15: is a tool that improves the graphics of the game by adding shaders, besides optimizing the game giving great impulse of FPS, and options of ingame configurations for better performance.
MINECRAFT FORGE 1.15: is a necessary tool for you that likes to install Minecraft 1.13.2 Mods, it was designed to guarantee to the creators of mod a compatibility between mods of different authors.
MINECRAFT SHADERS 1.15: These are shaderpacks that work together with Optifine and allow you to have very beautiful graphics, with lighting, reflections and high quality shade (For Advanced Players).