Don't eat resin, like any other form of plastic it's probably not good for you for you to ingest. You also want to keep it out of reach of small children who might try to eat it or could end up choking on it.
Scraping or sanding the resin may produce small amounts of dust, while the resin is non-toxic and non-carcinogenic inhaling the dust can cause brething difficulties so wearing a work mask is a good idea. With any form of dust you want to keep it out of your eyes. Proper eye protection is always recommended.
Working with resin models is pretty straight forward but there are some other general safety precautions you should take.
Be careful with your glue, anyone that has worked with super glue has at some point gotten their fingers stuck together or to the parts they are handling. In most cases it's a midly annoying and uncomfortable experience, in more extreme cases it could require a trip to the hospital to get them apart. Volume control is essential, not only will it help prevent stuck fingers but it'll also help avoid excess amounts of glue on the model and help avoid leaving behind strings of glue on the surface or fingerprint impressions. Don't work too closely to the glue as the fumes and vapors can get in your eye which stings quite badly and in extreme cases could blind you. Make sure your hobby space is well ventilated when using any sort of glues or paint.
When cutting be careful, hobby knives are very sharp and resin will have move "give" than what you are used to from polysturene, it's much easier to cut through and you may find that your knife suddenly pops through it much faster than when working with plastic. Until you are used to working with it use less pressure and go at it gently until you develope a feel for how much resistance it provides. The same applies when drilling through resin, be very careful when applying pressure to the drill as it may suddenly pierce through the part with more force than expected. Make sure you have a cutting mat down to avoid damaging your table or work area.
Use eye protection, little flakes of resin, plastic, glue, or dust can cause a lot of eye irritation, or eye damage in extreme cases. Most of the time it's a non issue but sometimes you can't control where they going flying off to and you don't want that to be in your eye.
A dremmel tool can be an amazing asset for your workbench but always make sure to use safety glasses when using one, they are deceptively powerful. Parts can become lodged on the dremmel bit or go flying off at incredible speeds which can put your eyes at risk and easily blind you. Dremmel bits have also been known to shatter during use so always make sure to have safety glasses on when using one.