I use AutoCAD r14 for 2D and for 3D modeling I use Delcam PowerSHAPE (now it has been acquisition by Autodesk), it's back when I study in university. Later I change it depends on what company use/have. Last I use NX in work.

For tips and tricks you'll be find it more when you do more practice, it is difficult to say what need to do. But for basic I'll say :

• Create better defined sketch.
• Do feature based mod/operation first. For examples do fillet/chamfer last if can, do pattern feature not sketch. It'll be easier later when you need to edit.
• Learn how to modeling efficiently.

For starting software there are many option out there. But I can recommend you view of it, especially that has educational/hobbyist/free version.

• Fusion360 (with edu email).
• Solidworks (IDK, it has version that I mean or not, but this one have largest user base).
• Autodesk Inventor (with edu email).
• Solid Edge Community Edition.
• NX education license.
• ZW3D edu license.
• Creo (it'll force you to learn how to model efficiently)
• Onshape (cloud based CAD, just need web browser to modeling).
• FreeCAD (if you want FOSS)
• Shapr3D (works on iPad and Windows, will be great if you have apple pencil or graphic tablet), (with edu email).

All of them have similarities in how to do 3D modelling, each of them has pros and cons. Choose one that you like and master it, try other CAD package and you'll find which one is home to you. 😂

Keep practicing and be better.