First off, it looks good as it is. Well done! Also, it works and that's the important bit. Some things which help me:

• use equality constraints instead of repeating measurements for radii and lengths
• fillets can be added after creating the main shape, this simplifies the sketch
• if you know this will be mirrored, draw a quarter and mirror the extruded body in part design (you could use multi-transform here)
• use formulas, spreadsheets or reuse named distances if you want to change things later
• make extensive use of the Part Design workbench but sometimes dabble in another workbench because when they click you'll unlock a new set of combinations and turn FreeCAD into a sort of swiss army knife

Congrats on your first model 👏