I think you would be best decided to train first as most courses will include the correct kit lamp required to set their product.
I stick two gels nsi and Calgel and therefore have two lamps as your products won't be guaranteed if you don't use everything the trainer or supplier gives.
I recently had an issue with a wax cartilage which I have don't training for but used my expensive depilieve machine which is way better then the machine this other product uses and the cartilage kind of cracked or whatever anyhow they refused to even consider my complaint as according to their records I have not purchased the heater.
So be carefully doing your own buying before , this goes for people buying second hand facial machines etc too , just don't be in too much of a hurry and land up wasting money.
Rather plod along and make sure you get the correct gear , as insurance is so fussy these days as well as suppliers.