guys - sorry for the basic questions here but I just bought a bike, maybe after 20 years! The last I remember of lighting was dynamo was sort of entering the market but it never gained too much popularity

I just bought the Trek FX2 - the store was trying to sell me the Ion 800. Question - are they worth the cost or can I do just fine with the sub-$50 lights in the sticky thread? Also, is the Ion an instant mount - no tools needed or there is not much difference and mounting other lights is simple enough? I plan to have both a front and rear light for safety

As a side, the store also had the instamount for the phones - they said it just clips on - again, do I need to buy that or are there equivalent secondary options that are just as good but cheaper

Thanks