Yes, “waterside” works if you're unsure whether it’s a river or canal. “Canalside” is also natural for a canal. Saying “See you at the river/canal/water” works too, but “side” adds clarity. Example: “Let’s meet at the canalside café.” For bathing, “Let’s swim by the water” sounds more natural. Visit: https://theriversidedubai.com/

I live in the USA, and I don't know of any nearby canals. "Waterside" is a word and simply means at the edge of the water. "Riverside" is a word. "Canalside" is not a word. (I'm using m-w.com) I've never heard or read "canal side" used, but perhaps it's different for people near canals. I consider "see you at the river / canal / water" to be completely natural and correct.

I agree with John. Canalside sounds odd. It is not a word listed in any of my dictionaries. Most people would say, "I'll meet you BY the canal" or "I'll meet you by the WATERWAY. The word, "waterway", is the general term for a river or canal route. When talking about places on the edge of a body of water, it is common to use the general term, "waterfront". For example, many people say, "the ships are docked at the waterfront" or "the houses are built on the waterfront" or "the highway was built along the waterfront". I would only use "side" to describe a more natural, undeveloped area. For example, I'd say, "these flowers commonly grow by the waterside" or "we are going swimming at the seaside" or "there is a bike path along the riverside". Hope this is helpful

It'd be more natural to say "by the canal", but "riverside" and "waterside" are both perfectly fine. To me it also seems unnatural to use the preposition "at" instead of "by", but the meaning is understood either way.

(moved comment to answer)