Spell casting isn't recommended for beginners. As Lark told you - before 'jumping' immediately into spell casting you should be familiar with basic areas of magic that will help you understand spell casting better and magic generally as well.
Also, you shouldn't cast spells you don't need just to gain experience.
You shouldn't ask us which kind of spells you should cast - you should ask that yourself.
Advanced magic practitioners cast spells only when they need to, meaning spells aren't cast uncontrollably, randomly or with no reason.
Spells are the last solution for things in life... If you have a need to cast a spell - you cast it, if you do not - then you don't cast a spell.
For instance, I wouldn't cast a luck spell unless I needed luck for something or felt an urge to aid myself with a spell.
After you learn basic magic concepts and gain experience with 'the basics' - you don't just take a random spell and cast it. You should cast for SERIOUS reasons and only if you really need to - magic isn't a toy to play with at all.