How to add comments in pdf using adobe acrobat pro dc

Hi and thank you for tutorial. I need bookmark tools for rapid access to my favorite topics in a pdf file. But it is really expensive and relatively unnecessary to purchase a pdf editor just for using bookmark option. I suggest to use comment tool, because it is searchable instead of bookmarks with needs a full subscription. Do you have any idea or suggestion about this issue?

Can anyone read them or do they have to have acrobat pro to read the comments

Adobe reader me jo comment me information ho u se hm kese pdf karke download kre

thank you