Hi Christina,
I wouldn't say 13.0 to 13.2 would be a performance issue, yes as said you need to have the right sizing for 13.2 and the most necessary things is to have proper maintaince of the database like if you are using oracle make sure you recompile all the database objects, run the table analyze job, make sure oracle is set to automatic memory management and tablespace set to autoextend.
Also make sure the init parameters are set which ar documented in the installation guide. The best part of 13.2 is the portfolio is completely rewritten and performance is way much better.
And ad 13.3 is already out in market i could say you plan for 13.3 as problems like out of memory and xog issues are taken care in this version. Incase you would want your sizing to be done by CA please have a discussion with your account management team and they will help you with the sizing required for 13.2 or 13.3.
Regards
Suman Pramanik