I've done a fair amount of solo touring on bike and learned a few things.
- Choose a camp spot with lots of light remaining.
- Bivi and 1 x large tarp (cover both of you) is probably the most minimal. This way you can sleep on beaches. Places with minimal trees. Has a small footprint.
Practice putting up and knots.
Your main concern is water - can get very hot in May and you'll be sweating lots. Take at least 2 x full bottles & a water filter so you can drink / fill when you pass a water source. Sun cream and take a hat which can shield you from the sun. Maybe use a wet bandanna / buff to keep your neck cool.
Spread the weight of your gear & food over the whole bike - don't just use rear Panniers as the excess weight on uneven ground can snap your pannier frame.
Consider a lock for your panniers.
Obviously have all the tools to fix mechanical issues - always carry 2 spare inner tubes - again the excess weight puts more strain and more wear. You might want to consider the self healing tubes - has a goo inside which fills in small punctures. You can your cooking oil (olive oil) on your bike chain.
- Stock up on food / snacks as often as possible rather than carry it all. Having a quick scan on google maps can show you built up areas and shops.
- I found it pays to stop & talk to local people as you can find out local beauty / historic spots and you'll meet lots of nice people - it inspires them to get out and have an adventure
- Have room in the plan for spontaneity - my favourite experiences came from what was not planned.
- Bathe in Rivers / lakes
Hope this helps. Got me thinking about planning another trip for myself