This is just ellipsis of
"It might be a burden for me to make out presentation material and it might be a burden for me to give presentations twice a week."
So it remains singular.
"It's good to work and to play."
This is ellipsis for
"It's good to work and it's good to play."
Regarding your original sentence: nouns that are countable MUST have a determiner in the singular. I.e. "a presentation", "the presentation", "this presentation", "that presentation", "no presentation" etc. and not just "presentation". If you wish to have no determiner, it must be in the plural. So your sentence should be, like I wrote above,
"... and to give presentations ..."
Also, "make out" doesn't sound idiomatic here. Perhaps you meant something like "create" or "come up with".
Lastly, you can, and probably should, omit the second "to" in your sentence as well given that is being repeated as it is.