Replacing your battery with a bigger one can do no harm and might even have benefits in the form of lasting longer between clicks and giving you peace of mind. But if you have a problem other than the existing battery being knackered, in other words a problem of excessive current drain, then a bigger battery wont solve it.
In an ideal world you would start by doing some simple testing, preferably both measuring the current draw when the car is parked and the battery capacity. The first is easily done with a cheepo lcd meter such as
https://www.maplin.co.uk/p/uni-trend-ut203-dcac-current-clamp-meter-n41nc . The second isnt much more difficult simply requiring you to remove the existing battery, fully charge it, take it off charge and check the voltage decay every day for a week to see if there is an internal short - sometimes happens as the lead compound vibrates out of the plates, settles at the bottom of the battery and shorts out a cell . If the voltage decays only very slowly then put the battery under a known load which need be no more than a headlight bulb, and measure both the current taken and the time for the battery to half discharge , usually taken at about 12.2v . Then multiply the current draw by the time by 2 and you will get a rough estimated of the capacity of your battery.
The existing size of battery should be more than adequate with the battery in good nick and the current draw normal. If its knackered replace it. If the problem is excessive surrent draw then best place to start is removing fuses one by one and seeing which if any cause the reading on your meter to drop.
