you might want to invest in some anti-foam chemicals with a small pot like that, even a smaller batch is going to be a tight fit.
And whenever you do buy a bigger kettle, go ahead and get a 10 gallon pot - don't even fool around with anything smaller if you want to do 5 gallon batches.
Small batches are a good way to get started though - I still do some small batches on the stove and I have mashed those in a 10 gallon cooler. As long as you preheat it and keep the lid closed you will be fine
"Brewers make wort, yeast make beer."
"Brewing beer is neither complicated nor expensive. It's the responsibility of the brewer to make it as complicated and expensive as their spouse & budget will allow."