Going to second the recommendation to wait until you're older since your brain will be more fully developed and less impacted. Since the other comments haven't really touched on the how I thought I would speak to that. You've got a couple of different options depending on your needs.

A very cheap entry point would be a pipe, lighter, and a grinder, then you would get some flower grind it and smoke. The exact breathing and covering process can take a few tries to get right, but if you look up a video you'll have it in no time. This option is pretty smelly, as you are combusting flower, so if you want to be discreet I recommend airtight storage and a change of clothes for yourself. If you don't want to keep a pipe you could buy cones for rolling joints.

For a bit more you can get a cheap dry herb vape, which I would recommend. Doesn't combust so the smell fades faster and its not as rough on your lungs. For this you'll just need the vape and the grinder.

You could also go for carts and oil/resin vapes, but I wouldn't trust random carts so not really recommended. For this you'd probably want a 510 battery to smoke carts purchased somewhere reputable. If you go this route live rosin is less bad for you but goes bad faster and is pricier.

When it comes to where, I recommend outdoors somewhere secluded and private. Look for somewhere that will hide you and won't blow the smoke down to a populated place. Big bonus if its somewhere you're comfortable since that will lower your chances of having a bad time with your high.

Stay safe, remember its not worth drawing police attention just to get high.