Just wanted to know how to apply the りする to a verb when saying something like "I want to visit japan and eat food." I've seen "今度の 夏休みに 川に行ったり、海に行ったりします" but is it as simple as putting り after the ta-form for all things listed prior to the last action?
You can use 「～たり～たりします」 "do things like ~~ and ~~" to list two or more actions. So your sentence means...
In my next summer vacation I'll do things like going to the river and going to the beach. (～たり～たり implies you'll probably do other things too.)
If you want to say "I want to do things like ~~ and ~~", you can use 「～たり～たりしたいです」, as in:
In my next summer vacation I want to do things like going to the river and going to the beach. (～たり～たり implies you probably want to do other things too.)
To say "I want to visit Japan and eat food", you could use the て form for connecting the two verb phrases, and the たい form for "want to~~" (e.g. 食べたい、飲みたい、見たい、行きたい...), as in:
I want to visit Japan and (then) eat the food (there).