Deep Web search engines and searching the deep web always come with some risk involved. There actually isn't anything that can be considered risk free when searching the deep web. There is some deep web search engine that can help you locate the hidden material. You can try one of these.
Many of the deep web searches use onion URLs which are only viewable on a browser such as Tor. When accessing the information on the deep web it will be much slower than access the information on the WWW. The access time will greatly depend on the database you want to access and how long it will take to display.
My advice to you on this one: if you actually want to go deep diving and searching in the deep or dark web you should set up a PC that is dedicated to this only. Keep all your other devices off your network when you are searching the dark web. Only use a dedicated PC that has no personal information on it to do your searches with. You never know what you'll find or if one of your own devices can get hacked or corrupted. It is best to be safe when doing this.